The Trial of Arnold Blackwood

Arnold Blackwood wakes in the grounds of Lord Erebus's estate, but why is he there? He can work out that he would not be there without his Lordship's authority so he must be carrying out a job for the old man... his only hope is to pick up enough clues to figure out what he's supposed to be doing and complete his mission without Erebus catching on that Arnold is not in full control of his own facilities! As you are with him, you might as well give him a helping hand...