Flentak arrived on the Excalibur with Nix. Due to their belief that even verbal contact in another race's language is unclean, Apriori Flentak would not speak directly to the humans, instead having Nix speak and translate for him.
Flentak and Nix had traveled to the Excalibur so that they could capture Natchok Var, who was a fugitive holding onto unspecified Moradi secrets. Flentak demanded the return of Var and all of his data crystals, threatening to destroy Excalibur with a fleet of Moradi ships if he didn't comply. Var allowed Matthew Gideon to copy the data crystals before being taken into custody by Nix and Flentak.
They made Var to travel on his own shuttle, and then promptly destroyed it before it reached their own ship.