In 2262, the Drakh chose Lanas at random off the streets of Centauri Prime and implanted him with a sleeper - a piece of left-over Shadow Technology - and sent him to live in Babylon 5's Downbelow, where he would wait for the next six months.
The intent was to kill Sheridan as he lead a group of Interstellar Alliance officials through the area as part of an initiative to improve conditions on the run down areas of the station. The attempt was thwarted after Emperor Londo Mollari was told of the scheme by the Drakh Shiv'kala, as a test that he had learned his place. Mollari failed the test when he managed to circumvent his keeper and obliquely warn Ambassador Vir Cotto of the plot by mentioning the late emperor Kran (who had met a similar fate over a century ago) and the Lanas's name. Vir managed to intercept Rem as Sheridan's procession drew near and the sleeper was killed with the unexpected intervention of the techno-mage Kane.