Will Burrows es un chico de 14 años que tiene una particular afición que comparte con su padre: a ambos les encanta excavar en busca de tesoros y nuevos descubrimientos. Así descubre que, bajo el mismo Londres, existen túneles que no constan en ningún mapa y puertas olvidadas durante siglos. Pero… ¿adónde llevan? Un día el padre del muchacho, el Dr. Burrows, desaparece misteriosamente luego de descubrir unas raras personas que andan por la ciudad. Will decide ir en su busca con la compañía de su único e inseparable amigo Chester. Lo que no saben es que se encontrarán con un mundo paralelo al suyo gobernado por extraños, peligrosos y despiadados personajes... ( )

It's been a while since I read the first four books, but this didn't disappoint. I quickly got back into the story and I enjoyed the new developments this book brought. ( )

This series is turning into one drawn out infomercial. Every time it should end the writers come back with “but wait, there's more”. Are they under some sort of contractual obligation to produce 6, or heavens forbid, even more books out of this one story, so that they have to keep dropping old plot points and introducing new ones?

The real shame is that the writers write well and could have woven many more stories out of all the plot details they put into just this one. If you've gotten this far then it's too late to save yourself, you'll buy the next (and next and next?) to see how the story ends, just like a smoker who can't quit even as he dies of cancer. ( )

The outer crust is under attack by the subterranean Styx who are turning ordinary humans into walking bombs and incubators for their eggs, and only Will Burrows and his band of retired commandos stand in their way--but the Styx also have problems of their own.