A fun YA series that I couldn’t quite make myself finish. It’s a great romp, taking us from present day leafy academic Oxford to the jungles of Mexico and a hidden remnant of Mayan civilisation that is safeguarding superior alien tech which the rest of the world isn’t quite ready for. It’s the kind of read where problem after problem just gets flung at the heroes, never quite giving them time to catch their breath. A breakthrough moment comes when our hero is deciphering an ancient Mayan text that appears to be gibberish – until he reads the individual syllables out loud and realises he can actually understand them because it’s as close an approximation to modern phonetic English as the Mayan alphabet will allow. After that, the presence of time travel is a given, and it becomes so clear that he is his civilisation’s legendary founding hero that I wasn’t actually that interested in finding out how.