Under the instructions of Travis Marshall, Beth Dorsey took the Wormwood device, hidden inside a University of Tallahassee backpack, to the offices of Miami Metro Homicide, bypassing the metal detector at the visitor's entrance by using Angel Batista's key card. There, following Travis' explicit instructions, Beth asked for Lt. Debra Morgan, telling the officer on duty that she had information for Debra concerning DDK Wormwood. After being told that Debra was in the field and not at the office, Beth waited for her at Miami Metro Homicide.
Dexter, arriving back at the office before Debra, noticed Beth sitting near the entrance before he did some internet research on Steve Dorsey. When Debra arrived, she was told by the officer on duty that Beth had information on DDK and Wormwood. At the same time, Dexter found a picture of Steve and Beth together. Realizing that it was Steve Dorsey's wife that he had seen when returning to the office, he looked out into the waiting area and saw Debra escorting Beth to the interrogation room. Dexter noticed the backpack's logo, and Beth pushing an activation button hidden in one of its straps. Jumping into action, Dexter quickly pushed Beth past Debra and into the interrogation room, and used his body weight to close and hold the door behind her. Dexter ordered Debra to get everyone out of the building, and Debra pulled the fire alarm and her voice to execute an evacuation.
Dexter successfully kept Beth from opening the door, which sealed her in the interrogation room with the active Wormwood device. Beth began to cough up blood, quickly succumbing to the gas. Although Dexter had been able to contain Beth with Wormwood, he was exposed to a small dose of the gas. While not enough to kill Dexter, it was enough to weaken him, leading him to lose consciousness later on while he was stalking Travis at the marina where Dexter kept his boat, Slice of Life.
As part of the work that Travis Marshall started, he created the device known as Wormwood with the intention to "poison mankind." After he knocked out Sergeant Angel Batista, he found his badge from the Miami Metro Police Department. Travis thus decided it was a sign from God indicating where Wormwood should be activated.
- Travis Marshall - Wormwood was known by police to be his work before its deployment, although until Beth activated the device, it was unknown where and what form Wormwood would actually take, other than being a poison gas.
- This is the first crime scene in the series where a mass murder was intended, but prevented. Mass murders were previously committed by Gene Marshall (seven by arson) and Santos Jimenez (four by chainsaw). Later, it's revealed that Oliver Saxon had killed seven children by setting a fire.