Caro-Kann Fantasy: the ...Qb6 Battery

Against the Fantasy (3.f3), 3...Qb6 hits b2 and d4 together. After 4.Nd2 e5, the natural grab 5.dxe5?? runs into 5...Bc5 — d4 has vanished, f2 is pinned, and the g1 knight is stuck. Note it needs 4.Nd2: against 4.Nc3 the same plan does not work.