Each installment of the Mysterious Benedict Society series explores the fundamentals of teamwork. The friendship and inter-reliance of the four children serves as the bedrock of each book in the series. In The Perilous Journey, this theme becomes especially prominent when the children choose to go on a dangerous mission to save Mr. Benedict and Number Two, who are integral members of the Mysterious Benedict Society. While the children are the core members, their families and allies are also essential. By choosing to rescue Mr. Benedict and Number Two against the adults’ wishes, the children prove that they can make a big difference and do difficult and dangerous things when they work together. In fact, given how difficult it is to save Mr. Benedict and Number Two, the children’s efforts are crucial to the success of the rescue.

There are a few times in the book when certain characters reject teamwork. Whenever they do so, things tend to go badly. For example, Mr. Curtain continually resists Mr. Benedict’s offers of collaboration. He is only interested in his own evil schemes and does not realize that if he and his brother worked together, their collective genius could allow them to accomplish great things.