The spies put Flopsy up for ransom in exchange for Oscar's mum. Surely, the Grand Master won't be able to resist and Oscar will finally be reunited with his mother? Oscar's mum leaves a covert message in his favourite magazine. She's still being held captive by SKUL and is ill. She is in desperate need of some medicine, which is in her locker in MI9 headquarters. Oscar is very worried, but also overjoyed that his mother has contacted him. The mission of the day is to capture the Grand Master. MI9 have yet to succeed, but Carrie has a plan. What's the thing the Grand Master loves more than anything? Flopsy. Lure Flopsy out and surely the Grand Master will follow. They devise an elaborate plan to screen all white rabbits in the country for a fictitious disease, Blue Ear. They find Flopsy and the Grand Master! Just when the spies are about to capture the Grand Master, he escapes, leaving Flopsy behind. Oscar confesses to Frank and his fellow spies what he's been asked to do. Carrie comes up with yet another brilliant plan. Exchange Oscar's Mum for Flopsy. It couldn't be more perfect - MI9 get the Grand Master once and for all and Oscar is reunited with his Mum. The location is agreed and both MI9 and SKUL stand on opposite sides of a bridge. The Grand Master is within their grasp. Oscar sees his mum for the first time in years. He's overcome with emotion but, in a shocking and painful twist, things go horribly wrong.