the wheels come off
Things go disastrously wrong; a situation devolves into ruin or chaos. But it's this point in the film where the wheels come off the story, and the whole thing ends up looking like a big, unfunny joke. Where the wheels come off for most people is the failure to set aside any meaningful savings to go towards a pension or a mortgage.
the wheels come off
things go disastrously wrong (causing an enterprise to fail). 2006 Sunday Times There is not much a captain can do when the wheels come off and batsmen and bowlers underperform.