The BAU travels to Houston to investigate a series of murders that have occurred near construction sites and abandoned buildings. Because the murders appear to be random, the team believes the killer could be a homeless person. Meanwhile, everyone is noticing an apparent change in Reid's behavior.

The team is called to Montana to investigate the case of four kidnapped and murdered women. When another woman disappears, the search leads to a man who apparently has assumed the identity of his dead partner.

The BAU investigates a series of murders that appear to be connected to a killer who jumps trains and chooses his victims based on their proximity to the railway.

The team pursues a copycat serial killer who is recreating the techniques used by past famous murderers.

When a new type of chemical warfare is released into the open air, the BAU must act quickly to find the source before any more innocent people are exposed.

The BAU team tracks a serial killer who keeps the eyes of his victims as souvenirs.

The BAU team races to help Hotchner find The Reaper and save his family before it's too late.

The BAU follows the mental decline of a con artist whose schemes have become so complicated that he begins to eliminate the people involved in them.