Conversation so far:
Is there anything special revealed about Andy Bernard's character in Season 3?
Early season episodes reveal Andy Bernard's anger issues, displayed when he finds his calculator encased in Jell-O.
Does Andy Bernard have any rivals at work?
There is rivalry with Dwight Schrute over whether Andy Bernard's title is higher than that of Dwight's Assistant Regional Manager, fueling an intense power struggle.
Does Andy Bernard leave his job at any point in Season 3?
A producer's cut of the episode explains Andy Bernard's departure from subsequent episodes as due to being sent to anger management training.

Question: When does Andy rejoin his job?
Self-contained rewrite: When does Andy Bernard rejoin his job?