D. Garnet Harding

When a violent tremor shakes a Manhattan office building and only one survivor is found, Walter surmises that its cause is rooted in his research with William Bell many years ago.

Anna, enraged at the increasing audacity of the Fifth Column attacks, enlists Ryan in an attempt to wipe out the Fifth Column in one fell swoop. Meanwhile, Father Travis (recurring guest star SCOTT HYLANDS -- Night Heat), following Vatican orders, asks Jack to leave the church. Plus, Lisa meets her grandmother, Diana (recurring guest star JANE BADLER) -- who Anna said was dead -- for the first time. Recurring guest stars also include ODED FEHR, JAY KARNES, ROARK CRITCHLOW, NICHOLAS LEA and CHRISTOPHER SHYER.

The team recovers a Roman plate that holds research on a synthetic gill unit tied to the research of a Professor Prendergast. Judson loses the plate when he and the curator are attacked while Gabe and Mac track the doctor to an insane asylum where he insists he is from Atlantis.