Infinite (The Infinite Quest)
The Infinite was a spaceship that was forged during the Dark Times.
According to the legend, whoever discovered the ship would receive their heart's desire. Three data chips were needed to find its secret location. Captain Kaliko, Ulysees Meregrass and Gurney had the three chips.
Baltazar was also after the chips, and murdered the chip carriers to get to the ship. He also used the Doctor and Martha Jones to get the location and hijacked the TARDIS to get there. The vessel did indeed have the ability to show people their heart's desire: it provided Martha with a romantic image of the Doctor, and untold riches for Baltazar, but the Doctor successfully prevented the vessel from showing his heart's desire. Ultimately, the Doctor destroyed the vessel. (DW: The Infinite Quest)