The clock reads 4:23, and I picked that (although I might have erred in other versions) to reference Book IV, line 23.

At the beginning of Book IV, Dido realizes she’s in love with Aeneas, the castaway that charmed her with his stories of suffering and adventure on the seas. But she’s not happy about it. She says, “Agnosco veteris vestigia flammae,” or “I feel again the spark of that former flame.” This is in line 23 of Book IV.