Complex sentence: On a refueling stop in Jakarta, Tintin, Captain Haddock and Professor Calculus are on their way to Sydney when they chance upon their friend Skut (introduced in "The Red Sea Sharks"): now personal pilot for aircraft industrialist and eccentric millionaire Laszlo Carreidas.
Split into simpler sentences: On a refueling stop in Jakarta, Tintin, Captain Haddock and Professor Calculus are on their way to Sydney when they chance upon their friend Skut, whom they met during "The Red Sea Sharks". Skut is now personal pilot for aircraft industrialist and eccentric millionaire Laszlo Carreidas.