Two days later, "Monaghan" was underway for the decisive battle of the war, the Battle of Midway. The Japanese sailed for the capture of the Midway Atoll with a complex battle plan, but U.S. naval intelligence revealed the plan to American commanders, who thus knew when and where to find the Carrier Striking Task Force of the Japanese attackers. Although outnumbered, the Americans sank four enemy carriers in air actions beginning on the night of 3 June, along with a heavy cruiser. Through the first two days, "Monaghan" screened , then late on the morning of 5 June was ordered out to rescue men of a downed seaplane. At 1830 she reached the side of badly damaged "Yorktown," joining the group of destroyers struggling to save the carrier and guard her from further damage. The penetrated the destroyer screen the next day and sank both "Yorktown" and , the carrier remaining afloat another 16 hours before she succumbed. "Monaghan," , and attacked and badly damaged the submarine.