The Devil's Triangle — Mark Robson

Sam and Callum are still stranded in the parallel world, having been pulled across by the dangerous energy of the Bermuda Triangle. Now they've found Sam's mum they are desperate to find a way home... at any cost. Meanwhile Niamh is convinced that her brother is alive and not dead as the authorities suspect, but she needs to find out what really happened to the boys before her father is convicted of their murder.