The DNA bomb was an explosive designed by the hologram woman to latch on to John Hart's DNA. Knowing he would find some way around it, she split it into three cannisters and one eye, which she entrusted in a Blowfish, and told John it was an Arcadian diamond. She created a Riftstorm, which took the Blowfish and cannisters to 2009 Cardiff. John killed her and used his vortex manipulator to ride the Riftstorm to Cardiff. The Blowfish was shot and killed by Jack Harkness and John collected the cannisters and the eye. The DNA bomb was activated, but John Deadlock sealed Gwen Cooper to him, forcing Torchwood Three to find a way to stop the bomb. Owen Harper injected John with blood samples of Torchwood workers and the bomb fell off. They threw it through the Riftstorm John first came from. It b