Try to stay with me. So when Hannah, Aria, Emily and Spencer found out about Mona, they thought she was the leader of the A team. Then later in the series, Spencer found out about Toby being in the A team. Then about 4 oder so episodes later, Spencer joined The A team. When her Friends found it everything changed. Turns out that Mona isn`t the leader. Red mantel is. Red mantel is believed to be Ally, but some people say different. So the A team is Spencer, Toby, Mona and Red coat.