Vintage. No date. (First published 1935.) c 1960s (No dustjacket.)

From biggles.info : Whilst flying in England, Biggles and Algy are forced to land by fog and find a mysterious hidden landing ground. When an unknown plane lands, Biggles climbs aboard to investigate and is accidentally trapped on board when the plane takes off. The plane lands near Newcastle and Biggles escapes only to be pursued. He meets a young lad who is travelling to London. This lad is ‘Ginger’ Habblethwaite who is to share many of Biggles’ adventures in the future. Ginger is sent to seek help, as Biggles has injured an ankle but when he returns Biggles has gone. Ginger gets in contact with Algy and puts him on the trail. Meanwhile, Biggles is being held captive in a nearby house and it doesn’t take Algy and Ginger long to find him. Ginger sets fire to an outhouse as a diversion and Algy enters the house to rescue Biggles. Reporting things to the Intelligence Branch of the Air Ministry, they are surprised to be informed that there is no trace of any secret airfields. Everything has been cleaned away. Following a clue from Algy, who had seen a map, Biggles, Algy, Smyth and Ginger fly to Germany and arrive at a seaplane base. Here they have an unexpected encounter with ‘Blackbeard’, one of Biggles’ captors. Flying away, they find their plane has been emptied of fuel and this forces them down. Help from the British Consulate Office in Danzig gets them more fuel. A chance encounter with the original mystery aircraft enables them to follow it to its base in Russia. Here they find loads of similar aircraft. Ginger and Biggles go to explore, leaving Algy and Smyth with the aircraft. Biggles and Ginger are separated and Biggles gets into the enemy camp. Biggles is captured, but saved by Ginger who shoots his captor in self-defence. They return to their aircraft but find it has gone! Smyth is at the scene and able to explain that Algy was forced to fly it to safety, due to search parties. A meeting place has been arranged but Algy is unable to make it, as the plane has become bogged down in its new landing ground. Ginger steals one of the mysterious enemy planes and with this they all fly to find Algy. Ginger has also stolen some apparently important documentation. Freeing their own plane, our heroes try to fly to Sweden but a lack of fuel forces them to ditch just off the coast. They are followed by Blackbeard who lands nearby but cannot find them due to fog. Running aground on what they think is a sand bar, Biggles and his colleagues haul their airplane up what turns out to be a river. Escaping to the nearest Swedish town, Biggles, Algy and Smyth are trapped in a restaurant by Blackbeard and his men. Ginger gets them out by having them arrested. Meeting with the personal assistant to the British Consul in Stockholm, Biggles explains what he has discovered and the police release them all to return to England. Flying to England becomes a desperate chase as Blackbeard’s seaplane and three other planes try to shoot them down. They are saved by RAF planes waiting to meet them. The plans Ginger had stolen were for a raid by thirty flying boats on Great Britain but with advance notice the raid is foiled. Biggles, Algy, Smyth and Ginger all receive money as a reward and Ginger’s money will be used to teach him to fly and learn engineering.