“Hamlet: […]I prithee, when thou seest that act afoot, / Even with the very comment of thy soul / Observe mine uncle:[…]”
“Possibly some chemical experiment was afoot; possibly----Well, it was no business of mine to speculate upon why he wanted it.”
“In San Francisco and in New Jersey, to quote two other examples, plans are afoot to subsidise new commuter line construction or existing operations out of toll revenue from state highways or bridges.”