Peril.

When Revealed: Remove all attachments and discard all tokens from the highest cost ally you control and attach it facedown under The Lockholes.

Forced: After The Lockholes is explored, return the attached ally to its owner’s control, faceup and ready.

“Lockholes, as they call ‘em: the old storage-tunnels at Michel Delving that they’ve made into prisons for those as stand up to them.” —Tom Cotton, The Return of the King