Spike has to leave his dying father's bedside to investigate a bomb threat at a nearby research and development company. Apparently, a security guard found a strange bag with wires hidden in a garbage bag and called it in. The building was being evacuated but the people on the lower levels refuse to leave , believing that they are experiencing a fire drill. When Sam finds another bag near the room they're in, he tries to get the civilians out. Two bombs go off, trapping everyone underground. No one was killed but one woman was pinned by rubble. Spike then finds a larger, more complex chemical bomb rigged with infrared and motion sensors, estimated to produce a bigger explosion. SRU then gets a call from a potential bomber, but it is apparent that he's not the culprit as the bomb is too complex. Police then come knocking at his door. Turns out, the culprit is one of the civilians trapped underground, determined to get revenge after the research and development firm he worked for framed him for selling out company secrets when their stock dropped. Spike is able to intuitively figure out that the code for deactivating the bomb is the bomber's mother's name numerically. Having saved the day, Spike returns to his father's side.
- Hugh Dillon as Ed Lane
- Amy Jo Johnson as Julianna 'Jules' Callaghan
- David Paetkau as Sam Braddock
- Sergio Di Zio as Mike 'Spike' Scarlatti
- Clé Bennett as Rafik 'Raf' Rousseau
- Enrico Colantoni as Gregory 'Greg' Parker
- Appearance of Babycakes.