L the ProLogue to Death Note: Spiraling Trap is the third in a series of Death Note video games. The story is set before the Kira investigation depicted in the original manga series.

The player assumes the role of a rookie FBI agent who is knocked out during an undercover investigation, with Naomi Misora or Raye Penber depending on the gender selected. The player wakes in a strange hotel setting laid with the difficult traps found previously by other FBI agents. Possessing a Communicator, the player is assisted by L in their escape, feeding him information gathered while investigating their environment.

Similar to a point and click investigation game, you are tasked with moving through the different rooms and floors of the hotel. Each room has various different items you can click on, such as pillows, drawers, safes, clocks, and lamps. Investigating these different items in each room will either enhance the story, unlock a sweets recipe (to be used in the L Communicator Mode), add an item of interest to your bag, or trigger a trap. L will warn you if you have no checked everything in a single room, especially if you have missed anything important. Its best to check the same areas several times as new items may spawn in already checked areas. After completing a floor, often times a trap will need to be diffused to unlock the next one.