After a violent attack on someone very close to Anna, she delivers a message that the Vs don't feel safe and will be leaving while she also gives a list of possible Fifth Column members to Chad hoping he'll investigate to help in finding them. Meanwhile, Erica and the team try to track down a scientist who may have created a weapon that the Visitors are afraid of.
Elenco: Elizabeth Mitchell , Morena Baccarin , Alan Tudyk , Brittney Irvin , Charles Mesure , Christopher Shyer , David Richmond-Peck , Joel Gretsch , Laura Vandervoort , Logan Huffman , Lourdes Benedicto , Mark Hildreth , Morris Chestnut , Scott Wolf .