A peaceful picnic becomes a thrilling adventure when Tom, Pippa, Zoe and Andy discover two strange men and a suitcase filled with top secret papers. The Adventurous Four face their biggest challenge when they are captured and held in an undergrand cave. Will they escape in time to raise the alarm? A peaceful picnic becomes a thrilling adventure when Tom, Pippa, Zoe and Andy discover two strange men and a suitcase filled with top secret papers. The Adventurous Four face their biggest challenge when they are captured and held in an undergrand cave. Will they escape in time to raise the alarm?