Mark Sivertsen

The team are dispatched to a destroyer to probe the bizarre death of a sailor, discovering he was deeply immersed in an addictive fantasy role-playing game and may have been bent on exacting revenge on his arch rival.

The BAU travels to Chicago to investigate a series of mass murders, after teenagers in a missing persons report become the main suspects.

The detective suspects Captain Stottlemeyer's girlfriend Linda could be a murderer.

Hank's increasing volatility forces a confrontation with Jesse and trouble at work. Skyler pressures Walt to make a deal. Gus' actions have severe consequences.

While working with a professional football team, Jonathan and Mark learn that one of the players is hooked on drugs supplied by the team doctor.

Things get complicated when Mary takes on the case of Leo Billups. Leo saw his mother murdered and is going to testify against the people who killed her.