His hair was greyer and his voice seemed huskier, but George Clooney still looked every inch the matinee idol as he climbed back into his old scrubs, slung a well-worn stethoscope round his neck and bid farewell to the TV drama that made him famous.
The actor, who resigned from the role of Dr Doug Ross on ER 10 years ago to pursue Hollywood stardom, led a cast of old hands paying their respects to the show, whose hospital doors slam shut for the last time on 2 April.
Thursday night's episode saw Clooney re-united with returning colleagues including Juliana Margulies, who played his love interest, Carol Hathaway. Viewers were taken from Chicago's fictional County General Hospital to Seattle, where Ross and Hathaway relocated a decade ago.
The two characters, who are now married with children, tried to persuade a grandmother, played by Susan Sarandon, to allow her late grandson's organs to be donated. After Clooney's smooth-talking alter ego won Sarandon round, Hathaway learnt a kidney went to "some doctor in Chicago" who turned out to be their former colleague John Carter, played by another member of the original cast, Noah Wyle.
Though limited to only half a dozen scenes Clooney's return tied up some loose ends to the storyline of his character's relationship with Hathaway, one of television's great on-off love stories. At the end of ER's fifth season, Ross disappeared to Seattle, leaving behind a heart-broken Hathaway, who discovered soon after that she was pregnant with his twins. Viewers witnessed the moment they were reunited but, until now, had been left with only a vague idea of the couple's ultimate fate.
Thursday's star-studded episode was a pressing reminder of how ER has declined since its launch in 1994. It was once the most popular and lucrative show on American television, winning 21 Emmys and garnering nearly 30 million viewers. Today, it is lucky to attract even a quarter of its old audience.
NBC's decision to axe the show (there are three more episodes to air) is part of a wider trend: all channels are losing audience share in an increasingly fragmented market and cheaper reality programmes or chatshows are replacing many dramas. Jay Leno will fill ER's slot next season.
ER has also seemed to have lost its edge compared to rivals like the medical drama House, the most popular scripted programme on television. ER's cast has chopped and changed too. The show was No 1 in the Nielsen charts in 2001 but is now ranked 49th.
The Clooney comeback, which airs in the UK on 14 May, was a reminder of what might have been; it also featured former stars Anthony Edwards, who played Dr Mark Greene, Laura Innes, who played Dr Kerry Weaver, Sherry Stringfield, Alex Kingston and Paul McCrane.
Critics were broadly positive. Verne Gay, from the New York paper Newsday said the episode was "a brief, fond and generous farewell" and "the plot was classic ER, tragic and hopeful".
Ken Tucker, from Entertainment Weekly, said: "I'm only half-joking when I say that his performance probably did a lot to increase organ donations around the country: When Doug Ross, in that superlatively reassuring murmur of his, tells you that 'You can change lives for the better' ... you want to fork over your retinas."
The show was aired with almost no fanfare or promotional trailers from NBC. As late as Thursday, the channel refused to comment on rumours of Clooney's return. Apparently this was at the insistence of the actor, who banned them from using his comeback for commercial purposes.
Small to big screen: Other converts
Eastwood started out on a low-brow soap opera called Rawhide, on which he played a cowboy called Rowdy Yates.
Aniston, one of Hollywood's most lucrative female leads, largely owes her star status to the comedy series Friends.
His film Hancock grossed $624m but 20 years ago Smith was an unknown who won a role in The Fresh Prince of Bel Air.