As Elizabeth welcomes Britain’s first woman prime minister and Charles meets a young Diana Spencer, an IRA attack brings tragedy to the royal family.

Margaret Thatcher visits Balmoral but has trouble fitting in with the royal family, while Charles finds himself torn between his heart and family duty.

Jerry’s family lives it up at the Plaza for free, thanks to Elaine; the fumigation of Jerry’s apartment disables Kramer’s taste buds.

When Enterprise is attacked by an unidentified enemy ship, the crew must work frantically to get their new phase canons to operate. Meanwhile, the captain charges Hoshi with finding out…