In 1954, Beldeanu began preparing the assault on the Romanian embassy: he travelled several times to Switzerland, acquired the needed weapons and tools, and held training sessions with the other members of the group (Ion Chirilă, Stan Codrescu, Dumitru Ochiu and Tudor Ciochină).
Around 2:00 AM, Aurel Şeţu, the embassy's driver (and possibly a Securitate agent) returned and entered into an altercation with Codrescu and Ochiu, following which Şeţu was shot.