Read a structural report without overreading it
Reachability, missing links and cycles answer different questions.
Unreached is about the chosen start
A passage is reachable when at least one sequence of existing choices leads there from the selected start passage. An unreached draft may be intentional. It becomes a problem when you expected readers to find it. Changing the start can change the report without editing a single connection.
A missing destination is not an ending
A choice with an unassigned or deleted destination is reported as missing. In rehearsal it is disabled, so the reader cannot fall into an invisible scene. A passage with no choices and no ending mark is reported as an unmarked dead end. Mark an ending explicitly when that stop is deliberate.
Loops and escape routes
A cycle group is a strongly connected set: within that group, passages can lead back to one another. A single passage pointing to itself also counts. A cycle is not automatically an error. In the example, returning to the quay creates a loop, but the reader can still take another route to an ending.
A reachable passage with no route to any marked ending is a different finding. It means the graph offers no escape to an ending from there, even if the passage has several choices. Inspect that part of the map. The app does not require every story to end, but makes the structure explicit.
What a shortest path means
The ending report lists one shortest route by choice count from the start. It is not the only route, the most interesting route or a complete playthrough test. Equal-length alternatives may exist. Text length and reader pace do not affect this graph distance.