Taboo Season 2: Everything We Know

'Colonnade' is the code name for a figure within the network of American spies working against The East India Company and the Crown, evading both identification and capture. Throughout the show, there is clearly a larger group of espionage agents at work; the British, the Americans, and quite possibly the French. Hardy dropped a tidbit to Entertainment Weekly not long after the climax of season one:

"We're on to the next stage. The key really is Colonnade. When he says, "We are Americans," James is very ambiguous with how much information he's going to give. In his mind, you will know when the time is right."

There are other characters who clearly know more than they are letting on; Countess Musgrove, a French socialite (real name Genevieve Decoux) works for the Americans as an agent against the British. Codenamed 'Carlsbad,' Musgrove is approached by Lorna who requires the "codes for the flags," to identify The Good Hope as a vessel friendly to the Americans, as the fugitives sail towards The Azores.

When Delaney agrees to keep Carlsbad's identity from Solomon Coop in exchange for safe passage, he adds in an extra dangling carrot - Delaney will "plug the leak" in the American Intelligence network, by silencing Dumbarton - permanently. Season two could feature a 'quid pro quo' relationship between Colonnade and Delaney, though don't expect anything to be plain sailing - there's too much at stake.