Michael has been working on the Marionette Project longer than anyone else, including Amanda. He is Amanda's top assistant and does his best to keep the loose ends tied between all of the different workgroups in the lab. While Amanda leads the biochemistry department, Callinway is often seen as the head because of his high authority. He's fully committed himself to the project and wishes to see his research better the world.

Michael is generally agreeable and sympathetic, making him very easy to get along with. He usually plays a mediator role for disputes amongst his colleages.

While he's on good terms with most of the other scientists at Amanda's lab, some are bitter about how she obviously favorites his opinions over the others'. Michael is very good at guessing what Amanda is thinking and knows how to get her to see things his way, but also knows when to back off, as she's very stubborn. Their colleagues may not be fond of the favoritism, but Michael is often the only one who can convince Amanda to consider different options.