By Martyn Herman
LONDON (Reuters) - The problem with addictive TV box sets is that when the credits roll on the final episode it leaves a void.
That moment gnaws away at the millions of fans entranced by the magic of Roger Federer down the years, but on Friday he produced a display of such technicolor brilliance to crush Andy Murray in the Wimbledon semi-final that they can rest easy.
This show may run for a while -- starting with Sunday's final against his great rival Novak Djokovic.
Swiss Federer, 34 next month, scaled heights that even his most loyal subjects thought they might only witness again by rummaging through dusty DVDs of his 17 grand slam titles.
British 28-year-old Murray, bidding for his third Wimbledon final, showed incredible resilience but was powerless to prevent a 7-5 7-5 6-4 defeat.
"I don't know if he's close to his peak," Murray, who did not manage to win a single point on Federer's first serve in a gripping second set, told reporters. "But that's definitely the best he served against me."
Murray may opt to watch his brother Jamie in the men's doubles final this weekend while Federer gets the chance to avenge last year's five-set defeat by Djokovic and add a record eighth Wimbledon title to his glittering collection on Sunday.
Top seed Djokovic also won in straight sets on Friday, beating gallant Frenchman Richard Gasquet 7-6(2) 6-4 6-4 to reach his fourth Wimbledon final.
Looking ahead to a 40th meeting between the world's two best players, Djokovic said: "We shouldn't spend too much words about Roger. We all know how good he is. He's the greatest ever.
"This is where he loves to play. It's his court. It's going to be probably the biggest challenge I can have."
When a clinical Djokovic moved two sets clear of 21st seed Gasquet the outcome was inevitable and hundreds of fans headed out to refuel before the day's eagerly-anticipated main course -- Murray's third meeting with Federer on Centre Court lawn.
Federer won the first in the 2012 final but a few weeks later Murray gained revenge to win Olympic gold -- a moment that launched his career to a new level that resulted in the U.S. Open title later that year and the Wimbledon crown in 2013.
Since then Federer has added another set of twins to his family, but no more grand slam titles.
But there is a glint in his eye this year.
He has sauntered through the draw, losing one set and, more remarkably, one service game, against Gilles Simon on Wednesday.
The winners are flowing, there were 56 on Friday compared to just 11 unforced errors. Nearly half his serves were unreturnable and the two hours seven minutes he took to outclass Murray took his total court time for the fortnight to 10 hours.
If he serves like he did against Murray there is every chance he can reverse last year's result.
"Definitely it was one of my best serving days of my career," Federer, who faced a break point in the first game but from then on bamboozled Murray, told reporters.
Federer timed his attacks to perfection.
He broke Murray with a wickedly dipping backhand in the 12th game to win the opening set and the pattern continued.
Federer won all 19 points when he landed his first serve in the second set.
Murray produced heroics, and even a second serve ace, to save five set points in a 15 minute game at 4-5 in the second set, the fans roaring their approval.
Federer did not blink though.
Instead, he held serve to love, and launched new wave of attacks, earning a sixth set point which he converted with a guided volley after running Murray ragged.
Murray could only pray Federer's level would dip.
Instead, the best was saved until last.
With Murray's hopes hanging by a thread at 4-5 he belted a forehand volley into a vacant corner but Federer flicked his wrist and sent an angled backhand across Murray's bows.
"That's sometimes the stuff you can come up with, it's awesome if it happens on Centre Court at Wimbledon in a situation like that, no doubt about it," Federer said.
But what of Sunday's installment?
"Big," he said.
It should be unmissable.
(Editing by Pritha Sarkar)