Max and Liz leave school for a couple hours to take a drive through back country roads. They're cruising along when a horse suddenly appears in the middle of the road. Max looses control of the jeep as he swerves to avoid hitting the horse. They crash. Liz is okay - just a few scratches. Max's is unconscious - bloody forehead against the steering wheel.
Max is rushed to the hospital. Liz overhears the doctor requesting blood samples. Liz calls Maria to tell her what's happened. Michael grabs the phone from Maria and asks Liz what's going on. The school's principal is notified of the accident. He in turn tells the school guidence counselor/undercover agent the news. She sees this as perfect opportunity to get the proof she's been searching for. She instructs her partner to get to the hospital right away. Michael and Isabelle arrive just as the nurse is drawing blood from Max's arm. They immediately begin scheming to get Max's blood sample. Liz asks what they've done in the past - when they get sick. Isabelle explains that they don't get sick. Isabelle suggests they use some of Liz's blood. Liz explains the doctors can tell male blood from female blood, so they have to find a guy.
Maria is sent to recruit her and Liz's longtime friend Alex. Alex, not knowing what he's getting himself into, has many reservations. Liz convinces him to allow them to draw his blood and switch it with Max's. Michael flirts with the nurse and switches the blood samples without her noticing. An undercover agent dressed as an orderly is upset that Michael was able to get to Max's blood sample first. He lurks around attempting to gather evidence.
Max has a super speedy recovery. The doctor wants to keep him overnight for observation. Max begs his mom not to make him stay in the hospital. The doctor agrees to let Max go home provided he takes it easy. Alex demands an explanation of why his blood was needed. Liz thanks him but tells him that she can't tell him what's going on. Alex assumes Max is on drugs, so Liz allows him to believe the lie.
Max, Michael, and Isabelle are on to the agents following them around. Michael, Isabelle and Maria follow an agent to his motel room. They sneak into the room when the agent leaves. They find a phone number written on a piece of paper. They dial the number and find guidence counselor Topolsky on the other end.
Meanwhile, guidence counselor/agent Topolsky tries to get Alex to tell her what he knows about what happened at the hospital. She slips something into his softdrink that causes his nose to bleed a few moments later. Alex goes into the restroom to clean up his bloody nose. He throws the bloody tissue into the garbage. After he leaves, Topolsky goes into the restroom and retrieves the tissues and puts them in a plastic bag. She later tells Alex that she knows that his blood was switched with Max's at the hospital and she has friends who can help him out and keep him from getting into trouble. She wants him to write down everything that happened and sign the document. Alex is afraid of getting into trouble, but is suspicious of her involvement. Liz asks for his help in finding out who she's working for. Alex demands answers. Liz assures him that she's on the right side.
Alex goes to Topolsky and pretends to cooperate. Liz stops by her office demanding to talk about Alex and his strange behavior. She attributes it to her making new friends this year. While Liz and Topolsky are in the hallway talking, Alex checks out her computer. It's apparent that Liz is trying to keep Topolsky out of her office. Topolsky returns to her office to find that her cover has been blown. Alex has accessed her FBI e-mail. Topolsky tells them they're wrong if they think they've just helped themselves. She tells them it's not over just because they know who she is. She tells Liz she was on her side and she hopes Max doesn't end up in the wrong hands without her there. She gathers her things and leaves.
Alex thinks that he deserves an explanation after all he's done. He tells Liz he's going to walk if she doesn't tell him the truth. She tells him she can't. Alex walks away.
ROSWELL THEME SONG "HERE WITH ME" from the CD :ANGEL By DIDO