When the narrator chains Fortunato to the staples and and he doesn't resist because he is so drunk.
When the narrator starts piling the bricks to trap in Fortunato. Eventually he "comes to" and Montresor can tell this by the rattling of chains and a low moaning cry.
Fortunato fully wakes, and he realizes that what Montresor is doing isn't a joke and that there is no way for him to get free and eventually gives up. Montresor finishes putting up the bricks and the last thing he hears is the jingle of the bells. "No mortal" has messed with Fortunato's tomb for 50 years.