diff --git a/tools/subagent_spawn b/tools/subagent_spawn
index 090d64e..b0291e7 100755
--- a/tools/subagent_spawn
+++ b/tools/subagent_spawn
@@ -31,9 +31,18 @@ name=${name:-$(/bin/date +%s%N)-$$}
 [ -n "$OLLIE_SESSION_ID" ] && name="${OLLIE_SESSION_ID}__${name}"
 cwd=${cwd:-$(pwd)}
 
-# Prepend parent identity so the child always knows who spawned it.
+# Prepend parent identity and plan so the child always knows who spawned it.
+parent_plan=""
+if [ -n "$OLLIE_SESSION_ID" ]; then
+    plan_file="$OLLIE/s/$OLLIE_SESSION_ID/plan"
+    [ -s "$plan_file" ] && parent_plan=$(cat "$plan_file")
+fi
+
 prompt="[parent_session_id=${OLLIE_SESSION_ID}]
-[session_id=${name}]
+[session_id=${name}]${parent_plan:+
+[parent_plan_start]
+${parent_plan}
+[parent_plan_end]}
 $*"
 
 kv="name=${name}