diff --git a/scripts/kb-lint.sh b/scripts/kb-lint.sh
index 4b8b933..72dd330 100755
--- a/scripts/kb-lint.sh
+++ b/scripts/kb-lint.sh
@@ -23,6 +23,7 @@ def pages():
 # Names that a wikilink may point at: exactly the pages pages() reports. Deriving this
 # once keeps linting and link resolution from disagreeing about what exists.
 live = {p.stem for p in pages()}
+live_paths = {p.resolve() for p in pages()}
 
 for p in pages():
     rel = p.relative_to(kb)
@@ -70,8 +71,16 @@ for p in pages():
     text = re.sub(r"^```[^\n]*$^```[^\n]*$", "", p.read_text(errors="replace"), flags=re.M)
     rel = p.relative_to(kb)
     for m in re.finditer(r"\]\((?!https?:|#)([^)#\s]+\.md)", text):
-        target = (p.parent / m.group(1)).resolve() if not m.group(1).startswith("/") else (kb / m.group(1).lstrip("/"))
-        if not Path(target).is_file():
+        target = (p.parent / m.group(1)).resolve() if not m.group(1).startswith("/") else (kb / m.group(1).lstrip("/")).resolve()
+        # A link INSIDE the bundle must land on a page that belongs to the bundle: `is_file()`
+        # alone also accepted a target parked in .AGENTTRASH/, which is gitignored — green here,
+        # a dead link on every machine that pulls (#57 again, in markdown clothing). A link that
+        # leaves the bundle is allowed: ../../AGENTS.md is the operating contract, not bundle
+        # content, and it is real on disk.
+        if kb in target.parents:
+            if target not in live_paths:
+                violations.append(f"{rel}: broken relative link -> {m.group(1)}")
+        elif not target.is_file():
             violations.append(f"{rel}: broken relative link -> {m.group(1)}")
     for m in re.finditer(r"\[\[([^\]|#]+)", text):
         # wikilinks resolve by filename anywhere in the KB (Obsidian semantics) — but only
diff --git a/tests/kb-lint.bats b/tests/kb-lint.bats
index cc8dfc8..9f87af6 100755
--- a/tests/kb-lint.bats
+++ b/tests/kb-lint.bats
@@ -134,6 +134,21 @@ EOF
   [[ "$output" == *"broken wikilink -> [[log]]"* ]]
 }
 
+@test "a markdown link into the quarantine is broken" {
+  # #57's failure mode wearing markdown instead of brackets: the relative-link check was a
+  # bare is_file(), so a link that lands on a page waiting in .AGENTTRASH/ passes this gate
+  # and points at nothing on every machine that pulls — the quarantine is gitignored. Both
+  # spellings count: relative, and bundle-absolute with a leading slash.
+  mkdir -p "$KB/.AGENTTRASH"
+  printf 'no frontmatter, quarantined\n' > "$KB/.AGENTTRASH/gone.md"
+  printf -- '---\ntype: reference\n---\nRelative: [gone](.AGENTTRASH/gone.md)\n' > "$KB/rel.md"
+  printf -- '---\ntype: reference\n---\nAbsolute: [gone](/.AGENTTRASH/gone.md)\n' > "$KB/abs.md"
+  run bash "$LINT" "$KB"
+  [ "$status" -ne 0 ]
+  [[ "$output" == *"rel.md: broken relative link -> .AGENTTRASH/gone.md"* ]]
+  [[ "$output" == *"abs.md: broken relative link -> /.AGENTTRASH/gone.md"* ]]
+}
+
 @test "a wikilink to a live page still resolves, in any directory" {
   # The narrowing above must cost nothing: filename-anywhere semantics is the point.
   printf -- '---\ntype: reference\n---\nSee [[good]].\n' > "$KB/sub/other.md"