Jon meanwhile has been doing an admirable job of not thinking with his dick and staying loyal to the watch while working undercover. It's starting to slip, though: he likes some of the wildlings and he finds Ygritte's eyes and smile alluring despite her commoner looks.
Tormund has various hilarious tall tales to tell. Jon sees giants on mammoths. They all have a sing song. Ygritte is a bit sad that there are only a few hundred giants left in the world. Then everything happens at once: Jon is attacked by the eagle posessed by the ghost of a man he killed, and Mance finds the watch's hilltop camp. Except there are more dead watchmen than Jon told Mance were on the ranging.
Somehow or other Mance doesn't have him killed for lying, but instead tells him he's going on a mission tomorrow and he'd better prove himself by killing some watchmen. Ygritte also manages to persuade Mance that she and Jon are "dancing" under Jon's cloak at night. Which they haven't yet despite much snuggling for warmth, but now wants Jon to make her honest. I like Ygritte: she knows what she wants and she's persistent about getting it.
Edit to add: I just remembered Ben Stark's complaint when Jon first mentioned wanting to join the Watch, which was that Jon had not known love and did not know what he was giving up. What are the chances that when he finds out, his attitude changes somewhat?