To do this step, the player must obtain a Pack-a-Punched weapon.
Now, you have to go the alleyway in the direction of the animal labs, outside at the M1 Carbine wall-buy location.
Look outside the barrier: Far in the distance you will notice a control panel on a pillar. Shoot it with your upgraded weapon or throw a grenade at it. If done correctly, you should hear Samantha say:
Do you want to play a game? Let's play hide and seek!
Several items around the pillar will be emit a green glow and start to fly up in the sky and disappear.