TarkovHead

Head to an infected location, preferably the , throw the given by the Therapist, and kill the zombies in the gas cloud as they swarm toward it. Be sure to equip any gas protection gear: , , , so the gas doesn't damage you.

If you run out of grenades, the Therapist offers a barter for one in exchange for a Black Division gas grenade or a Blood Sample (which can also be obtained from the same scientists as in the ), , and (see the ).