St Peter Being Freed from Prison
This episode is recounted in the Acts of the Apostles (12: 1-6). The scene shows Peter being awoken by the Angel and taken out of his cell, while the guard is sound asleep and notices nothing.
The fresco was originally attributed, along with all the others, to Masaccio.. It was in 1838 when the first scholar attributed it to Filippino Lippi and this theory was accepted by all later critics.