In the Season 3 episode, "The Greatest Gift," Pete accidentally uses a Christmas artifact to create a parallel timeline where MacPherson is in charge of the Warehouse, Artie has been banished from the Warehouse and imprisoned, and Myka and Claudia were never recruited into the Warehouse. As the only one who remembered the original universe, Pete gathered his team together to fight MacPherson. MacPherson killed Artie in the same way he died in the original universe, moments before Pete erased the alternate universe and restored the original timeline.
