A Dog Called Grk — Joshua Doder

When Tim is followed home by a dog on the street, he's determined to find out who the friendly stray belongs to. But with a little investigating, Tim discovers that Grk's owners don't live in his town, or even in his country. Max and Natascha Raffifi, Grk's owners, have been kidnapped with their ambassador parents by the evil Colonel Zinfandel and taken to a prison in Eastern Europe! Tim knows he's about to undertake a mission his parents wouldn't exactly approve of. He sneaks out of the house in the middle of the night with Grk, catches a taxi to the airport, then hops a plane to Stanislavia. Together he and Grk will have to break into a high-security prison, pilot a helicopter, and make a nail-biting run for the border in this high-octane, international adventure.