Giac was a Sorcerous Supernumerary tasked with guarding Suzy in the tower's prison section at level 61620 after she was captured by the Artful Loungers near the Rain Reservoir during the events of Lord Sunday.
Giac was a gloomy and often nervous Sorcerous Supernumerary. He, like most Sorcerous Supernumeraries accepts the fact that they are failures. After joining Suzy, he appeared to lose some of his sadness. Suzy remarked that he is like Arthur in some way. He is often childlish and ignorant like most Piper's children. He is shown to be quite obedient or simply afraid in a way that he was reluctant to use Noon's chess set even though everyone is at top fighting. He readily accepted to change sides when offered by Suzy but was aware of something to do before changing sides. He mentioned prefering a brightly colored uniform than his old, dark Sorcerous Supernumerary attire.
He was included in the assault force to the Upper House to open several elevators with Suzy, her Raiders, and Doctor Scamandros , who was quite happy to meet a fellow Sorcerous Supernumerary from the Upper House . The latter leaving the Upper House to find his test results. He is unofficially granted the rank of Colonel by Suzy. It is presumed that he died along with the others during the rush of Nothing in the Incomparable Gardens . It is unknown if he is revived by the New Architect .