Heartbeat (1992)

S15E26 Accidents Happen

A recently released inmate is drawn back into a covert scheme. Meanwhile, Debbie begins to turn her life around when a familiar face reappears. In the midst of this, a local boy lashes out after losing his pet, crafting a bomb that he hides in the Aidensfield Police Station. The explosion claims Helen's life, leaving Rob heartbroken and reeling from the tragedy.