They are a pair of agents of the Bureau of Time Travel from the year 2175, given the seemingly inconsequential duty of protecting pistachios, the favorite snack of their boss, Mr. Block. Cavendish, the tall grey-haired one, is the more serious of the two who always attempts to ensure their mission succeeds, while Dakota, the shorter one who wears a track suit, is more laid back and cares more about incidental matters than their missions. They are known to argue and be disagreeable with each other.
A semi-recurring gag in early episodes involves Milo attempting to purchase pistachios from them and his bad luck causing them to lose their pistachios. After their plans to preserve pistachios get ruined every time they encounter Milo, Cavendish comes to suspect that he is an enemy agent who has been sent to foil their mission. However, in "Missing Milo", after Cavendish accuses Milo of thwarting them, Milo explains to them how Murphy's Law works and why things go wrong around him.
- Starting from "Perchance to Sleepwalk", Balthazar and Vinnie have been relieved of their pistachio duties and demoted to cleaning Renaissance-era toilets.
- Early reruns of the show's first episodes - "Going the Extra Milo"/"The Undergrounders" and "Rooting for the Enemy"/"Sunny Side Up" - had cameos by Cavendish and Dakota inserted into them that did not appear in the original broadcasts (perhaps implying that the duo had time-traveled into those episodes).