There are 31 minutes on the clock at Twickenham and Scotland are careering towards the most hideous, morale-sapping, humiliating Calcutta Cup mauling.

Even the most naively optimistic fan expected a sound beating from England, a resounding continuation of the 36-year wait for a win here.

Even the most gloomy pessimists among them would have struggled to paint the cataclysmic picture of doom unfolding as half-time approached.

Five tries down. No points scored. Leadership? Accuracy? Aggression? Forget it. England were thundering through slapstick defence like buffalo running at gnats.

Then, the unthinkable happened.

BBC Scotland's Andy Burke was sat in front of some supremely confident England fans

BBC commentator Andrew Cotter wasn't expecting a comeback either - but honestly, who was?

England 31-7 Scotland - At least it's not a granny-ing

"Well, at least we won't get nilled."

Relief is the vibe when Stuart McInally hauls Scotland on to the board with half-time approaching. His team are flailing when up steps their captain.

McInally blazes forth to charge-down Owen Farrell, scoop up the bouncing ball, and gallop all the way home from over 40m.

It looks like nothing more than a consolation but hey, it's a damn impressive run-in.

BBC's John Beattie was a member of the last Scotland team to win at Twickenham in 1983

England 31-19 Scotland - Is the comeback on?

Hang about, don't switch over to Pointless just yet. This is more like it. This gives Scotland a sliver of hope. Two glorious tries in three bonkers minutes.

Ali Price is at the forefront, getting a couple of touches before Darcy Graham pin-balls his way over in the corner. Then the scrum-half collects his own delicious chip-kick and puts Magnus Bradbury cantering in.

The camera cuts to Gregor Townsend, but if his mind is whirring with thoughts of a comeback, he doesn't show it.

England 31-24 Scotland - 'Give Darcy Graham the freedom of Hawick'

Now, Scotland are snarling. Finn Russell, their play-maker, is swaggering and probing and hauling the English defence this way and that. The Scots are rampaging forward with an intensity and vigour that makes you wonder how the hell they could be so awful barely 20 minutes ago.

From a maul on the left, a phenomenal, floating Russell pass sends Sean Maitland haring for the line, and the full-back puts Graham scooting over at the corner. All of a sudden, it's a one-score game.

Stuart Hogg and Darcy Graham both hail from the Borders town of Hawick

England 31-31 Scotland - 'Someone introduce Farrell to his arms'

Ah yes, Owen Farrell and the no-arms tackle. We've seen this before. The England fly-half races up to tackle Graham and gets his hit very wrong, failing to wrap his arms and smacking the winger high as he kicks ahead.

It's a high-speed collision but Farrell faces a nervous wait as the officials decide his fate over the big-screen replays. Penalty only is the call, but many reckon the hit merited greater punishment. Greig Laidlaw misses from the tee but Scotland remain on top.

Former England international Austin Healey wasn't impressed with Farrell's hit

Scotty "Sumo" Stevenson is a renowned rugby broadcaster in New Zealand

Farrell's technique does not impress BBC presenter Dougie Vipond either

England 31-31 Scotland - Russell completes 'the greatest comeback since Lazarus'

What. Is. Happening? How is this possible? It's like sinking 12 pints and waking up hangover-free the next morning. It's like ordering pizza every night for a month and not putting on any weight.

Scotland's line speed is unlike anything we saw before the interval. Sam Johnson shoots up to close down Farrell's options, Russell is way ahead of him, picking off his opposite number's shovelled pass and racing under the sticks.

The comeback to end all comebacks is complete. This is dizzying stuff.

Former Scotland captain David Sole knows a thing or two about beating England

David Denton is one of a host of Scots to miss the Calcutta Cup match through injury

England 31-38 Scotland - 'Three minutes, boys...three minutes!'

Scotland haven't won here since 1983, remember. Bear in mind too they're without a raft of key players, in pretty poor form, and up against a monstrous England side, and you'd have said before the game that any victory would be up there with the finest in Scottish rugby history.

This is different, though. This is miraculous. If they can pull this off, it's up the parting of the Red Sea, the 2012 Ryder Cup and that woman who came back to life after having no pulse for 45 minutes rolled into one.

Scotland are off again, finding yawning holes in the English defence. Johnson explodes through one of them and he's away. The centre is like Alan Tait in 1999, a stampeding thoroughbred swatting off tacklers one by one. An unstoppable force.

He slaloms into the 22, bashes through two Englishmen and slams the ball down under the posts. The look of shock and elation plastered across his face pretty much sums up the national mood at this point. Cue mayhem.

What would injured Scotland captain John Barclay give to have been out there?

Olympic gold medallist Callum Skinner urges Scotland to hold on

The former First Minister got rather excited

England 38-38 Scotland - Ford scores, but Scotland keep the cup

It's too good to be true, isn't it? This is Scotland we're talking about. We're braced for Craig Joubert round two and the agonising non-penalty that cost Scotland a World Cup semi-final in 2015. We're expecting Harry Kane to arrive as he did at Hampden with an almighty pin to pop the Scottish bubble.

Scotland hold firm. England can only draw with a converted try. They bludgeon their way into the 22, moving the ball left and right. The clock ticks red. Jack Nowell, scorer of the first English try in what feels so long ago it is virtually a different game, is held up inches short with bodies writhing and squirming to halt him like a nest of snakes.

Phase after bruising phase goes by. Scotland are stretched and stretched again. Should they let England scored out wide and force a touchline conversion? They don't, and finally they snap in the worst possible place. George Ford spies a gap and zips inside Johnson to score under the posts. His conversion ties the game.

Deflation. Heartbreak. Pride. As a player, how do you feel after that white-knuckle ride, to be so hopelessly out of the contest then within seconds of winning it?

Former Scotland captain Kelly Brown was among many great Scots never to beat England at Twickenham

Former Scotland footballer Brian McClair enjoys the action

Broadcaster Kelly Cates is lost for words

At last, we can draw breath. It's hard to know what to make of it all. We're told it's the highest-scoring draw in Test history. More importantly, Scotland keep the Calcutta Cup for the first time in 35 years.

Ryan Wilson missed the match through injury but enjoyed getting his hands on the Calcutta Cup