OTL, lieutenant Viktor Ivanovich Ilyin deserted with two handguns, went Borovitsky Gate, in the Kremlin, and shot at a motorcad, killing its driver and lightly wounding a passenger, one of the four cosmonauts honoured this day. However, Brezhnev was unharmed.
So, TTL, Ilyin manage. to kill Brezhnev. Who would replace him? And what could happens next?