Loomis was a 21st century Human who was recruited by the Xindi-Reptilians in 2004 as part of their effort to create a bio-weapon with which to destroy Humanity.
As an employee at a blood bank in Detroit, Michigan, Loomis was recruited for his access to clients of all blood types, as well as his willingness to kidnap these people for money. Loomis agreed to supply the Reptilians, who had covertly traveled back in time from the year 2153, with victims of each blood type, allowing the Reptilians to augment their bio-weapon to maximize its lethal effect. Loomis was unaware of the true nature of his employers, at one point considering the idea that they were terrorists, although he did not allow this to deter him from continuing to accepting money for his illicit activities.
