coolly

"He was here," observed Drina composedly, "and father was angry with him." ¶ "What?" exclaimed Eileen. "When?" ¶ "This morning, before father went downtown." ¶ Both Selwyn and Lansing cut in coolly, dismissing the matter with a careless word or two; and coffee was served—cambric tea in Drina's case.

They walked in, not even wearing masks, and coolly robbed the bank of twelve thousand pounds.