Image source, Getty Images

We might have a few of you joining us for the first time today so it's worth reminding you of how the women's Ashes works.

It used to be decided by the outcome of a Test match, or series of matches, between Australia and England.

But reflecting the pre-eminence of white-ball cricket in the women's game a points-based system across all format has been used since 2013.

In this series, there are four points available for winning the one-off Test, plus two points for each of the six limited-overs games.

Australia are the current holders of the Ashes, so with a maximum of 16 available points need eight points to retain them.

Alex Hartley
Former England bowler on BBC Test Match Special

Image source, Reuters

Just a bit of turn for Ash Gardner but that's a ball Kate Cross could have left. She will be annoyed with herself.

This is where the meat of the game is at, this is where it will get exciting.

Alex Hartley
Former England bowler on BBC Test Match Special

Image source, PA Media

Kate Cross's best Test score is 11...

England quietly and calmly going about their business as milk singles off Tahlia McGrath.

The Aussie seamer is bowling a very tempting length, hanging it up there, attempting to draw these two into miscuing a drive into the hands of a fielder.

The final ball of McGrath's over strikes Wyatt on the front pad as the England batter attempts to work it it to leg, and there's a decent appeal. However, all parties concerned know that's slipping down leg.

On we go...

Australia's Tahlia McGrath speaking to BBC Sport shortly before play: "It was a nice finish to the day for us, it's crazy how much the momentum changes. We started the day full of confidence and some poor dismissals on our part and we left a few runs out there but to finish how we did I'm really happy.

"Healy has been leading from the front and every time she speaks it's so inspirational."

On the Dukes ball: "I've loved it, it's been so much fun and getting more out of it than a normal Kukooburra.

"It's going to be tough today and the game is certainly in the balance, it's about who starts better.

"How good is five day cricket? It hasn't disappointed.

"There's so many ebbs and flows in the game so trying to keep level. We're trying to play what is boring cricket and if we stay patient and disciplined, that's the plan of attack."

Sensible stuff from Kate Cross, thus far. Watching the ball carefully outside off stump, and getting forward decisively to Ash Gardner.

Cross nudges one through backward point to get Danni Wyatt back on strike. Offered a bit of width by Gardner the aggressive Wyatt biffs it through the covers.

There's a fielder out there to cut off the boundary, but positive intent showed by England so far.

Ffion Wynne
BBC Sport at Trent Bridge

Image source, Getty Images

England will be hoping that Australia's bowlers get tired, but Alyssa Healy has a lot more options to choose from than Heather Knight had.

It says quite a lot about their depth that Ellyse Perry hasn't even bowled in this innings yet.

Alyssa Healy goes with seamer Tahlia McGrath in tandem with Ash Garder, picking up where they left off last night.

McGrath finds a little bit of swing as she hangs the ball up outside off stump.

Danni Wyatt, who is a confident strokemaker, sees off five dots before thrashing the final ball through the covers for four. That was uppish, but she put the kitchen sink behind it. Wowzers.

England's bowler Kate Cross speaking to BBC Sport, shortly before play: "I'm really looking forward to it and be annoying and stay around for as long as possible and support Danni.

"You don't get opportunities to score runs for England as a bowler and I feel really valued that they think I can do the nightcap role. It's great fun.

"The mood has been pretty similar throughout and that's what Jon Lewis has brought to the dressing room. Test match cricket is an absolute rollercoaster. It does hit you hard when you're in the thick of it. We would have loved to been a few less down but we have the talent in the dressing room to chase that."

Ash Gardner's third ball beats ball batter, keeper and races away for four byes.

England will not mind that one bit.

A few balls later and Kate Cross leans forward and pushes at a delivery which squirts past slip and allows her to pick up a couple of runs.

Calm start by England.

Danni Wyatt takes guard.

Spinner Ash Gardner, on a worn day five pitch, has the ball in hand.

"Play" calls umpire Sue Redfern.

Strap yourselves in, here we go.

England stand on the verge of making history today. The 268 runs they need to chase down for victory will comfortably be the highest-ever successful run chase in women's Tests. The current best is the 198 made by Australia against England at Sydney in January 2011.

The highest fourth-innings total in this format was England's 245-9 at Canberra in January last year, as they finished agonisingly short of their target - just 12 runs, in fact, as the match ended in a thrilling draw.

On only seven occasions have a team scored more than the current Australian lead of 208 in the fourth innings - with six draws and one defeat.

Image source, Getty Images

The umpires - Sue Redfern and Anna Harris - have just walked on to the field and are swiftly followed by Australia's players, led by skipper Alyssa Healy.

England's unbeaten batters, Danni Wyatt and Kate Cross, punch gloves before a purposeful stride to the middle.

Alex Blackwell
Former Australia batter on BBC Test Match Special

Australia are on top of this game but England could do something special here. These girls haven't tasted the success of winning an Ashes so they will be hungry.

Right, we're a few minutes away from play getting under way at Trent Bridge.

Can England do this?

Thumbs up if you think they can score the 152 runs needed to win, thumbs down if you think England will fall short and lose.

Alex Hartley
Former England bowler on BBC Test Match Special

I'm nervous this morning. Went for dinner with Kate Cross last night and she said "I'm buzzing, I've always wanted to be the nightcap".

I'm glad she is confident. England just need to get through the first hour of play.

Image source, BBC Weather

There were some thundery showers around the UK on Sunday, but Trent Bridge was not affected and we got a full day of play in.

Thankfully, there is little chance of rain disrupting proceedings today with the forecast showing sunshine and few clouds.

We could potentially have the odd light shower, but it won't affect the chances of a result here.

Ffion Wynne
BBC Sport at Trent Bridge

Quite a stark contrast in team warm-ups this morning.

Australia's bowlers are, well, bowling - going through some intense drills and the good news for them is that Alana King looks absolutely fine (the leg-spinner was off the field last night with a sore elbow).

England, meanwhile, are playing football.