If you still insist on trying it for yourself, then here are some tips that we think might help you complete it: If you've reached level 47 in your core progression military rank, then you will be able to craft decoy grenades. As soon as you go near the barrier, in order to make sure zombies spawn and come from the barrier, throw your decoy grenade somewhere near the medical bay exit. You need as much time as possible to wait for the zombie to walk towards you and to time your shot, so the hand kills the incoming zombie. Given the small space, it is very easy to get run over by multiple zombies and die. Trust us, we've gone through this multiple times! Do it with a teammate if possible. They can train and distract the zombies away from you while you can focus on the barrier. Once your teammate has gone far away, luring a bunch of already spawned in zombies, they can kill one zombie. This way, a zombie will spawn in to make up for the dead zombie. And if you're standing by the barrier, there is a high chance for that zombie to spawn through that, making it easier for you to get another hand kill. If you want to perform this easter egg, do not forget to equip the Aether Shroud field upgrade. This field upgrade has saved our lives multiple times when overrun by zombies. It also helps you ignore the zombies while making your way to the barrier, increasing the chances for a zombie to spawn through that medical bay barrier. If you have successfully acquired one kill and the hand cool-down starts, a simple yet very effective strategy that we've found is to exit the medical bay through the particle accelerator door, making your way to the weapons lab, and then back to the medical bay. Making this whole loop will give you enough to reset the zombie spawns, and the cool-down will also finish. Once you're back in the medical bay after a whole loop, wait for the green lights to turn on and quickly stand by the barrier to ensure that a zombie comes through this barrier and not from somewhere else. Repeat the same. More number of zombies means higher chances of you getting those hand kills, as multiple zombies will come through the barrier if there are more. However, the issue is that the space in the medical bay is less, and you will easily get overrun by zombies. It is best if you leave around 10-15 zombies at the end of each round and then performs this easter egg.