Recs if you like The Jackal (Black Dagger Brotherhood: Prison Camp, #1; Black Dagger Legacy, #5)...

Limiting this to fantasy/sci-fi, these are books where the MCs are locked up for most of the book or it's a crucial part of the plot. This can include magical prisons, cursed towers, institutions of sorts, and probably more!

Black Dagger Brotherhood/Legacy/Camp/Wolven book series in reading order. Written by J.R. Ward

Black Dagger Brotherhood Series plus spin-off series. By JR Ward