As was the case with Season 2 of Invasions Mode, the final mesa that Mortal Kombat 1 players will visit during the Season of the Cryomancer is Rampart. Here, they'll find all manner of challenging enemies as well as four Klues just waiting to be solved. The first of these is called Atomic and is tied to the Mouthy node.
Mortal Kombat 1: How to Complete the ATOMIC Klue in Season 3 of Invasions
Solving the ATOMIC Klue should be relatively easy for most Mortal Kombat 1 players, are there just happens to be a Fatality with the word in its name.