Books in the The Gates of Avalon series

It had been more than a thousand centuries since the Old Ones disappeared. Who they were and where they went was a matter of heated debate amongst the scholars of Avalon. The old ones had left behind five great artifacts. Gates that opened pathways to the many worlds spread across all the plains of existence.For many centuries the ageless gates stood as monuments to the Old Ones. No one guessed or understood the danger until it was to late. The mighty warriors of Asgaard fell in a single night of blood and flames, Shangri La only lasted an hour. Even the Empire of the Four Realms could not stand against this new enemy.Now the darkness that enveloped Avalon was coming here and it was up to Theodore Schmidt, an old man, crippled and weary to stop it. This is the chronicle of that struggle.