diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 2f4f1ba..50dcf8d 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "throughline",
   "description": "Continuous, state-aware session memory for Claude Code. Captures what you did and what is (commands, file changes, decisions, and live git/PR state), then hands it off with judgment at session wrap-up. Readable, committable artifacts; binds to Claude's native memory.",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "author": {
     "name": "Dynamic Agency",
     "email": "support@dynamicagency.com"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 91273f6..bedc4d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,49 @@
 All notable changes to throughline are documented here. Format loosely follows
 [Keep a Changelog](https://keepachangelog.com/); this project uses semantic versioning.
 
+## [0.5.2]
+
+Hot-path perf batch plus issue #15, which turned out to have a second,
+un-cosmetic bug underneath it - caught by an independent code-review pass on
+this release before merge. Verified by the full 143-assertion suite plus
+shellcheck under both Homebrew and an `apt-get install shellcheck` Ubuntu
+container.
+
+### Changed
+- **One jq invocation per capture/prompt fire, not two**: `session-capture.sh`
+  and `session-prompt.sh` (the hottest hooks - every matched tool call and
+  every prompt submit) each separately resolved `session_id` via
+  `tl_resolve_sid` and then re-ran a full jq program to build the record line.
+  Both are now produced by a single jq call (`session_id` and the line joined
+  by a tab), removing the per-fire process. This matters most for
+  `session-prompt.sh`, which runs synchronously ahead of prompt processing.
+  The id is piped through the shared `clean` def (control-char/backtick
+  stripping) before joining, so the split is unambiguous even for a
+  session_id containing a literal tab; `tl_safe_sid` still runs exactly once,
+  as the single sanitizer. The split-and-sanitize step itself is a new shared
+  `tl_split_sid_line` helper in `_lib.sh`, not hand-duplicated between the two
+  hooks (an initial version did duplicate it verbatim - flagged by review and
+  factored out before merge, since that duplication is exactly the drift
+  class `tl_resolve_sid` itself exists to prevent). Cold-path hooks
+  (flush/precompact/onboard) are unchanged.
+
+### Fixed
+- **Issue #15**: `redact()`'s generic keyword+separator rule left an orphaned
+  trailing quote on a quoted secret value (`password="X"` redacted to
+  `password=***"` instead of `password=***`). No security impact on its own -
+  the secret itself was always masked - purely malformed output. The
+  value-capture group now distinguishes a balanced quoted value (`"..."`, both
+  quotes consumed) from an unterminated one (opening quote with no matching
+  close) from a bare unquoted run.
+- **Multi-word unterminated-quote leak** (pre-existing, found by review while
+  fixing #15 above): the unterminated-quote case's first fix stopped at the
+  first whitespace, like the bare-unquoted case - so a multi-word unterminated
+  secret (`password="open sesame`, no closing quote) only masked its first
+  word and left the rest in cleartext (`password=*** sesame`). This gap
+  predates #15 and was never specific to this release, but was caught here
+  because the new comment/CHANGELOG language claimed the unterminated case was
+  fully handled, and the case is now genuinely fully masked to match.
+
 ## [0.5.1]
 
 Calmer follow-up pass on the three cleanups v0.5.0's review deferred rather
diff --git a/hooks/_lib.sh b/hooks/_lib.sh
index d206be8..b16b71b 100755
--- a/hooks/_lib.sh
+++ b/hooks/_lib.sh
@@ -128,6 +128,30 @@ tl_resolve_sid() {
   tl_safe_sid "$_tl_raw"
 }
 
+# Split a "sid<TAB>line" string - the shape session-capture.sh's and
+# session-prompt.sh's single-jq-call optimization emits (session_id and the
+# formatted record line joined by one literal tab, so each hot-path hook makes
+# one jq call instead of two) - into the two pieces, sanitizing the id via the
+# same tl_safe_sid that tl_resolve_sid uses. Shared here rather than
+# hand-duplicated in both hooks: that duplication is exactly the drift class
+# tl_resolve_sid itself exists to prevent (see its comment above) - a future
+# change to the split or sanitization, edited in one hook but not mirrored in
+# the other, would silently desync how the two hot-path hooks derive a session
+# id from the identically-shaped jq output.
+# Args: $1 = the "sid<TAB>line" string. The id half is assumed to already have
+# passed through the jq-side `clean` def before being joined (both callers do
+# this), so it cannot itself contain a tab - the split below is unambiguous
+# regardless of what the raw, pre-`clean` session_id contained.
+# Sets (does not print) $_tl_split_sid and $_tl_split_line: an OUT-PARAMETER
+# pair, not a same-named-temporary collision guard, so despite the `_tl_`
+# prefix these are meant to be read by the caller immediately after the call -
+# the same convention tl_active uses for $_tl_active_reason.
+tl_split_sid_line() {
+  _tl_tab=$(printf '\t')
+  _tl_split_sid=$(tl_safe_sid "${1%%"$_tl_tab"*}")
+  _tl_split_line=${1#*"$_tl_tab"}
+}
+
 # Replace control characters (including newlines) with a space. Shared by
 # session-flush.sh and session-precompact.sh so their reason/trigger fields
 # can't break the `<!-- ... -->` marker they're embedded in. (The jq `clean` def in
@@ -306,16 +330,32 @@ tl_jq_redact_defs() {
   # "password X" still mask X. That aggressiveness is CORRECT for commands but
   # WRONG for prose (it eats the word after any keyword+copula, inverting
   # "password is not the problem" -> "password is ***"), which is exactly why
-  # prompts use redact_prompt below instead. Value group has no @ or /
-  # exclusion - it matches the sentinel when present, else the unbounded run up
-  # to whitespace/quote - so a secret containing either char is fully masked.
+  # prompts use redact_prompt below instead. Value group tries, in order: a
+  # BALANCED quoted value ("..."), consumed whole (both quotes included in the
+  # match, so the replacement drops them entirely instead of leaving an
+  # orphaned trailing quote - issue #15); the sentinel; an UNTERMINATED quoted
+  # value (opening quote present but no closing quote anywhere after it, e.g.
+  # truncated/malformed input) - by the time this alternative is even tried,
+  # the balanced alternative has already proven no closing quote exists
+  # anywhere later in the string, so it is safe (and necessary) to consume the
+  # REST OF THE LINE rather than stopping at the first whitespace: an earlier
+  # version of this alternative stopped at whitespace like the bare-unquoted
+  # case below, which silently masked only the first WORD of a multi-word
+  # unterminated secret (`password="open sesame` -> `password=*** sesame`,
+  # leaking "sesame") while claiming the case was fully handled - excluding
+  # only \r/\n (not stopping at end-of-string) so it can't cross into a
+  # different line of a multi-line captured command; then the bare unquoted
+  # run, which DOES intentionally stop at the first whitespace (a bare,
+  # unquoted "password X" has no signal that X is meant to span multiple
+  # words, unlike an opening quote). No @ or / exclusion on the unquoted
+  # alternatives, so a secret containing either char is still fully masked.
   def redact:
     _pem
     | _auth_scheme
     | gsub("(?i)\\btoken\\s+(?<t>[A-Za-z0-9._\\-]+)"; "Token ***")
     | _url
     | _prefix_tokens
-    | gsub("(?i)(?<k>\\w*(?:token|secret|password|passwd|api[_-]?key|access[_-]?key|credential|auth(?:orization)?|client[_-]?id)\\w*)(?<s>\\s*[:=]\\s*|\\s+(?:is|was|are)\\s+|\\s+)(?<v>\"?(?:\(M)|[^\\s\"]+))"; "\(.k)\(.s)***")
+    | gsub("(?i)(?<k>\\w*(?:token|secret|password|passwd|api[_-]?key|access[_-]?key|credential|auth(?:orization)?|client[_-]?id)\\w*)(?<s>\\s*[:=]\\s*|\\s+(?:is|was|are)\\s+|\\s+)(?<v>\"[^\"]*\"|\(M)|\"[^\\r\\n]*|[^\\s\"]+)"; "\(.k)\(.s)***")
     | _unmask;
   # Prose-safe redaction for user prompts (issue #5), and for the WebSearch
   # query / Task description branches in session-capture.sh (also prose).
diff --git a/hooks/session-capture.sh b/hooks/session-capture.sh
index 4149833..312798c 100755
--- a/hooks/session-capture.sh
+++ b/hooks/session-capture.sh
@@ -38,24 +38,37 @@ bufdir="$data/buffer"
 
 mkdir -p "$bufdir" 2>/dev/null || { tl_err "mkdir failed for buffer dir"; exit 0; }
 
-# Session id is resolved independently of the formatted line below (rather than
-# splitting both out of one combined jq call), via the shared tl_resolve_sid
-# (also used by flush/precompact) so it is derived identically everywhere a
-# buffer filename is keyed off it.
-sid=$(tl_resolve_sid "$input")
-# Drop records with no usable session id rather than poisoning a shared
-# "nosession" bucket that flush never stamps and onboard re-warns about forever.
-# Breadcrumbed like the other silent-loss paths below: currently unreachable
-# (Claude Code always supplies a UUID session_id) but if that assumption ever
-# breaks, the loss should be visible rather than untraceable.
-[ -n "$sid" ] || { tl_err "dropped action: no usable session_id"; exit 0; }
-
 # The redact/clean defs are shared with session-prompt.sh (via
 # tl_jq_redact_defs in _lib.sh) so the rule set can't drift between the two
 # capture-side hooks; the outcome($t) def and the tool-name dispatch below are
-# specific to PostToolUse and stay here. Concatenated into one jq program so
-# this remains a single jq invocation on the hot path.
-line=$(printf '%s' "$input" | jq -r --arg root "$root" "$(tl_jq_redact_defs)"'
+# specific to PostToolUse and stay here.
+#
+# Session id and the formatted line are produced by ONE jq invocation
+# (sid-tab-line), not two: this is the hottest hook in the plugin (fires on
+# every matched tool call), and a second full jq process just to re-derive
+# .session_id was pure overhead. The trivial `.session_id // ""` expression
+# below is byte-identical to tl_resolve_sid's own (_lib.sh) — only that
+# expression is re-inlined here; the actual SANITIZER (tl_safe_sid) still runs
+# exactly once, in shell, on the extracted id, same as tl_resolve_sid does. That
+# distinction matters: the historical desync bug this consolidation must not
+# reintroduce came from two DIFFERENT DERIVATION MECHANISMS (shell vs. jq)
+# disagreeing on a session id, not from two identical jq expressions — see
+# tl_resolve_sid's comment. Cold-path hooks (flush/precompact/onboard, which
+# fire once per session/compaction rather than per tool) are unchanged and
+# still call tl_resolve_sid directly.
+#
+# The id is piped through `clean` (control-char + backtick stripping, defined
+# in tl_jq_redact_defs) before being joined with the tab delimiter, so a raw
+# session_id that happened to contain a literal tab can never be misread as
+# the sid/line boundary — tl_safe_sid (run by the shared tl_split_sid_line
+# helper below, _lib.sh) maps every disallowed byte (control chars, tab,
+# backtick, space, ...) to the same `_` regardless of whether `clean` already
+# turned it into a space first, so this is a no-op for any session_id shaped
+# like an actual UUID (the only shape Claude Code emits today) and produces
+# the identical final sanitized id even in the currently-unreachable case of a
+# stranger one. A regression test locks in that capture and flush agree on the
+# filename for a tab-containing id.
+out=$(printf '%s' "$input" | jq -r --arg root "$root" "$(tl_jq_redact_defs)"'
   # Observable outcome from the tool result. The Claude Code Bash tool_response
   # exposes "interrupted" but NOT an exit code, so a plain non-zero exit is not
   # visible to a PostToolUse hook and is deliberately left unmarked rather than
@@ -74,7 +87,8 @@ line=$(printf '%s' "$input" | jq -r --arg root "$root" "$(tl_jq_redact_defs)"'
           or ((($r.exit_code? // $r.code? // $r.returncode? // 0) | tostring) != "0"))
       then " `[failed]`"
       else "" end;
-  (.tool_name as $t |
+  ((.session_id // "") | clean) as $sid
+  | ($sid + "\t" + (.tool_name as $t |
     if $t == "Bash" then
       "**bash** " + ((.tool_input.description // "") | redact | clean) + outcome($t) + " - `" +
       ((.tool_input.command // "") | redact | clean | clamp(200; "…[truncated]")) + "`"
@@ -130,9 +144,22 @@ line=$(printf '%s' "$input" | jq -r --arg root "$root" "$(tl_jq_redact_defs)"'
       # other branches rely on to preserve a literal `*` in content like a
       # glob pattern or command.
       "**" + ($t | clean | gsub("\\*"; "")) + "**" + outcome($t)
-    end)
+    end))
 ' 2>/dev/null) || { tl_err "jq filter failed"; exit 0; }
 
+# tl_split_sid_line (_lib.sh) does the tab-split + sanitize; shared with
+# session-prompt.sh so the two hot-path hooks can't drift on how they derive a
+# session id from this identically-shaped jq output — see its comment.
+tl_split_sid_line "$out"
+sid=$_tl_split_sid
+line=$_tl_split_line
+# Drop records with no usable session id rather than poisoning a shared
+# "nosession" bucket that flush never stamps and onboard re-warns about forever.
+# Breadcrumbed like the other silent-loss paths below: currently unreachable
+# (Claude Code always supplies a UUID session_id) but if that assumption ever
+# breaks, the loss should be visible rather than untraceable.
+[ -n "$sid" ] || { tl_err "dropped action: no usable session_id"; exit 0; }
+
 [ -n "$line" ] || exit 0
 
 tl_append_line "$bufdir" "$sid" "$line"
diff --git a/hooks/session-prompt.sh b/hooks/session-prompt.sh
index f1a25bc..59ab1bf 100755
--- a/hooks/session-prompt.sh
+++ b/hooks/session-prompt.sh
@@ -26,11 +26,16 @@ bufdir="$data/buffer"
 # why the breadcrumb lives at the data-dir root, not under buffer/.
 mkdir -p "$bufdir" 2>/dev/null || { tl_err "mkdir failed for buffer dir"; exit 0; }
 
-# Same shared session-id derivation as capture/flush/precompact so the prompt
-# line lands on the same buffer file as the actions it precedes.
-sid=$(tl_resolve_sid "$input")
-[ -n "$sid" ] || { tl_err "dropped prompt: no usable session_id"; exit 0; }
-
+# Session id and the formatted line are produced by ONE jq invocation
+# (sid-tab-line, split by the shared tl_split_sid_line in _lib.sh), not two,
+# for the same reason as session-capture.sh: this hook runs SYNCHRONOUSLY
+# ahead of prompt processing (see below), so a second full jq process per
+# keystroke-adjacent submit is exactly the wrong place to spend it. See
+# tl_split_sid_line's comment for why joining on a `clean`-passed id is safe
+# even for a session_id containing a literal tab. Cold-path hooks
+# (flush/precompact/onboard) are unchanged and still call tl_resolve_sid
+# directly.
+#
 # Build the prompt line. Three deliberate choices, all different from the
 # command capture path:
 #   1. redact_prompt, NOT redact: prompts are prose, and the command-tuned
@@ -42,13 +47,23 @@ sid=$(tl_resolve_sid "$input")
 #      inside that window slips past redaction. The final clamp(200) is what
 #      actually lands in the buffer; its ellipsis reflects the real length.
 #   3. Concatenated with the shared defs into one jq program (single invocation).
-line=$(printf '%s' "$input" | jq -r "$(tl_jq_redact_defs)"'
-  ((.prompt // "") | clamp(2000; "") | redact_prompt | clean) as $p
-  | if ($p | gsub("^\\s+|\\s+$"; "")) == "" then ""
-    else "**prompt** " + ($p | clamp(200; "…[truncated]"))
-    end
+out=$(printf '%s' "$input" | jq -r "$(tl_jq_redact_defs)"'
+  ((.session_id // "") | clean) as $sid
+  | ((.prompt // "") | clamp(2000; "") | redact_prompt | clean) as $p
+  | ($sid + "\t" +
+     (if ($p | gsub("^\\s+|\\s+$"; "")) == "" then ""
+      else "**prompt** " + ($p | clamp(200; "…[truncated]"))
+      end))
 ' 2>/dev/null) || { tl_err "jq filter failed"; exit 0; }
 
+# tl_split_sid_line (_lib.sh) does the tab-split + sanitize; shared with
+# session-capture.sh so the two hot-path hooks can't drift on how they derive
+# a session id from this identically-shaped jq output — see its comment.
+tl_split_sid_line "$out"
+sid=$_tl_split_sid
+line=$_tl_split_line
+[ -n "$sid" ] || { tl_err "dropped prompt: no usable session_id"; exit 0; }
+
 # Empty / whitespace-only prompts produce no line.
 [ -n "$line" ] || exit 0
 
diff --git a/tests/run.sh b/tests/run.sh
index 7974679..59bccc7 100644
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -174,6 +174,36 @@ hasnt "URL credential with no nearby keyword is not stored" "$PLAIN_LINE" 'hunte
 hasnt "internal sentinel never leaks into the buffer" "$PLAIN_LINE" 'TLREDACTSENTINEL'
 has   "URL host/path is preserved" "$PLAIN_LINE" 'example.com/data'
 
+# 2e10. issue #15: a quoted secret value ("...") is fully masked with NO
+#       orphaned trailing quote left in the output - the value-capture group
+#       used to optionally consume a LEADING quote but never a matching
+#       trailing one, so `password="X"` redacted to `password=***"` (the
+#       secret itself was masked; only the stray quote was cosmetic, but it
+#       is malformed output).
+cap '{"session_id":"T","tool_name":"Bash","tool_input":{"description":"quotedpw","command":"config: password=\"hunter2superlongvalue\""}}'
+QUOTED_LINE=$(grep quotedpw "$BUF/session-T.md")
+hasnt "quoted secret value is not stored" "$QUOTED_LINE" 'hunter2superlongvalue'
+hasnt "no orphaned trailing quote after the mask" "$QUOTED_LINE" '***"'
+has   "quoted secret value is masked" "$QUOTED_LINE" 'password=***'
+
+# 2e11. an UNTERMINATED quoted value (opening quote, no closing quote anywhere
+#       after it - malformed/truncated input) is still masked rather than
+#       silently falling through to cleartext, matching this rule's
+#       pre-#15-fix behavior for exactly that shape.
+cap '{"session_id":"T","tool_name":"Bash","tool_input":{"description":"unclosedpw","command":"config: password=\"hunter2superlongvalue"}}'
+hasnt "unterminated quoted secret is not stored" "$(grep unclosedpw "$BUF/session-T.md")" 'hunter2superlongvalue'
+
+# 2e12. a MULTI-WORD unterminated quoted value is masked IN FULL, not just its
+#       first token - an earlier version of the unterminated-quote fallback
+#       stopped at the first whitespace (like the bare-unquoted case), which
+#       masked only "open" in `password="open sesame` and left "sesame" in
+#       cleartext right after the *** marker.
+cap '{"session_id":"T","tool_name":"Bash","tool_input":{"description":"unclosedmultiword","command":"config: password=\"open sesame"}}'
+MULTIWORD_LINE=$(grep unclosedmultiword "$BUF/session-T.md")
+hasnt "second word of an unterminated multi-word secret is not stored" "$MULTIWORD_LINE" 'sesame'
+hasnt "first word of an unterminated multi-word secret is not stored" "$MULTIWORD_LINE" 'open'
+has   "unterminated multi-word secret is masked in full" "$MULTIWORD_LINE" 'password=***'
+
 # 2f. redaction applies to the Bash *description* field, not just command
 cap '{"session_id":"T","tool_name":"Bash","tool_input":{"description":"deploy with ghp_abcdefghij1234567890","command":"true"}}'
 DESC_LINE=$(grep '\*\*bash\*\* deploy' "$BUF/session-T.md")