On her way home from an all-night surveillance job, V.I. Warshawski's dogs lead her on a mad chase that ends when they find a badly injured teen hiding in the rocks along Lake Michigan. The girl only regains consciousness long enough to utter one enigmatic word. V.I. helps bring her to a hospital, but not long after, she vanishes before anyone can discover her identity.

As V.I. attempts to find her, the detective uncovers an ugly consortium of Chicago power brokers and mobsters who are prepared to kill the girl. before VI can save her. And now V.I.'s own life is in jeopardy as well.

Told against the backdrop of a city emerging from its pandemic lockdown, OVERBOARD lays bare Chicago's neighbours and their secrets in masterly fashion.