Chloe was an associate of the Torchwood Archive.
The Archive sent Chloe and Zachary Cross Flane to Emperor Merdiven's opening of his mother's library. Merdiven had retaken the thrown after the coup which had outed his mother fell. Zachary deduced Merdiven was an imposter who had arranged the event to kill those who might realise the truth and left him trapped in the late empress' library. (AUDIO: Empire of Shadows)