Simplify the following text for a Grade 7 native English-speaking person.
Original: The Narnians escape , thanks to Tumnus ' cloever plan , which leads Rabadash to make his father agree that they should take Narnia by invading Archenland .
Simplified: The Narnians manage to escape thanks to Mr. Tumnus ' clever plan , which leads Rabadash to convince his father that they should take Narnia by invading Archenland .