With the help of some friends, Taylor Calmus and his wife Heidi, a couple living in Los Angeles, California, have worked for three days on the installation of a long Rube Goldberg machine through the floors of their house. The aim of the operation: reveal the sex of their child in an original way. Thus, the chain reaction sets in motion of dozens of objects up to the last part of the machine, built only by friends to surprise to parents, the latter not knowing themselves also the sex of their baby.