The Other (Animorphs #40)

We can't tell you who we are. Or where we live. It's too risky, and we've got to be careful. Really careful. So we don't trust anyone. Because if they find us...well, we just won't let them find us. The thing you should know is that everyone is in really big trouble. Yeah. Even you.

Everyone thought Visser Three and Ax were the only Andalites on Earth–until now. The Animorphs have discovered two other warriors who escaped from Ax's Dome ship, and they may be able to help fight against the Yeerks!Gafinilan and Mertil were living their own quiet, secret lives on Earth, until they were caught on home video and shown on TV. With their keen instinct and quick Andalite tails, they could be a huge asset to the Animorphs. Except that Marco is suspicious. He's sure something's not right with these guys. Are they really Andalites–or is it a trap?