Prof. E. Gadd's time machine

Prof. E. Gadd's time machine is a device that appears in Mario & Luigi: Partners in Time. It was invented by Professor E. Gadd during the events of Mario & Luigi: Superstar Saga. Not much has been explained how it works, other than it is powered by a magnificent gem called the Cobalt Star, and it moves through time by opening time holes.

During the time machine's showcasing at Peach's Castle, Princess Peach uses it, along with Toadiko and Toadbert, to visit the Mushroom Kingdom's distant past. However, she comes into the time in which the kingdom is invaded by the Shroobs. The Cobalt Star is then destroyed in order to trap the Elder Princess Shroob, and with a last bit of energy, a Junior Shrooboid transports back to the present, wrecking the time machine and rendering it useless. The time machine's return, however, temporally opens a time hole in the castle garden, allowing Mario and Luigi to step back into the past Mushroom Kingdom. The time machine is later re-engineered to run off the energy illuminating from the numerous time holes in the castle, allowing the Mario Bros. to safely return to the present. The last use of the time machine is by Baby Mario, Baby Luigi, Baby Peach, and the younger Toadsworth in their farewell back to the restored past.

On the western microsite for the game, the console of the time machine was shown in more detail. Hovering the cursor over the levers and lights would cause the levers to move and both to make a sound. Pressing the buttons and switches would cause them to make sounds as well. The time machine could go to four locations: Peach's Castle, Bowser's Castle, the Toadwood Forest, and Hollijolli Village. Going to each location would show its respective scenery outside the windows.