WHO DO YOU TRUST? Agent Topolsky (guest star Julie Benz) reappears in Roswell, now terrified and desperate to warn the aliens that they are in great danger, but when Max (Jason Behr) and Liz (Shiri Appleby) refuse to trust her, she turns to Sheriff Valenti (William Sadler) for help in protecting the kids she previously tried to expose. Feeling that time is running out for all of them, a panicked Topolsky agrees to give Michael (Brendan Fehr) top-secret FBI evidence in return for his trust, but before they can meet, she is intercepted by her superiors and the evidence falls into the wrong hands. Meanwhile, Isabel (Katherine Heigl) is surprised to find that she has a lot in common with Tess Harding, a beautiful new girl in school (guest star Emilie De Ravin), and Maria (Majandra Delfino) yearns for more romance in her relationship with Michael. Colin Hanks also stars James Whitmore, Jr. directed the episode written by Thania St. John