chunk: The submarines hold up at an island to resupply, and during the night, the Advance tries to slip away from the Wonder. Tom knows that the Wonder and its crew is not certain of the location of the wreck, and is merely following the Advance, hoping to steal the treasure at the last moment.
  After the Wonder tries to ram the Advance, Tom and his father take to the heavy underwater cannons, and successfully disable the Wonder, leaving her damaged and immobile. Tom and the Advance seize the opportunity to push ahead.
  An engine mishap forces the Advance to surface off the coast of Brazil, where they are soon confronted by the Brazilian battleship São Paulo. Tom and his crew are captured and scheduled to be executed two days later, and the submarine turned over to the Brazilian government. Tom and his friends are held prisoners aboard the battleship.