Yesl: the Balkien from Antrobi

Yesl, a member of the Balkien race of beings from the planet, Antrobi, fourth in the Vegan System, meets Matt and his two siblings. Matt learns about Yesl and her two other crew members, Boongoo and Baingae, on their mission to Splogita, when they were attacked by an evil force dominating that planet. Matt and his family decide to help Yesl and her companions to retrieve their fallen spacecraft, whose wreckage has now become the center of an international media sensation. Years later, Matt meets his sweetheart, Erin, at an American university where he studies Astrophysics. Meanwhile, Yesl and some of her crew, rendezvous with an Antrobian rescue spacecraft looking for their lost ship. It then transpires that Yesl's home planet, Antrobi, is in grave peril from the evil force that had attacked them on Splogita. And thus, Matt and gang, along with Yesl, her crew and their rescuers launch a mission to return to Antrobi to liberate the Balkien race from the evil force's tyranny.