If you’ve ever checked a bag before a flight, or sent it off to be gate checked, then you may have wondered where it all goes and how every passenger’s bag manages to fit on the plane. A video from inside a cargo hold shows the careful luggage stacking that every flight requires.

In the video, an airline luggage handler fits 100 suitcases into the narrow space at the bottom of a plane. First, the handler makes his way to the very end of the luggage hold and lays down a mobile conveyor belt on the floor. Thanks to this belt, the handler doesn’t have to travel back and forth from the door to the very end of the luggage hold to carry and place the heavy luggage. Instead, a second handler located at the door pushes the luggage on the belt toward his co-worker.

As soon as they receive the checked bags, the luggage handler stores them all in an efficient way according to size. They line and stack them perfectly so the bags don’t shift during the flights. It’s a like a real-life game of Tetris.

As the luggage handler gets closer and closer to the door of the baggage hold, they move the belt with them until they don’t need it any longer. Despite the small, narrow space, the handler manages to fit every piece of luggage in the hold.

While many tend to think that luggage handlers throw our belongings around without any care for fragile items, this video shows us that the process (or at least this part of the process) is actually quite gentle and carefully done. That said, don’t start putting super fragile stuff, like musical instruments or bottles of alcohol, in your checked luggage — there’s a chance you won’t get them back in one piece.