The lives of stockbrokers, and how they get rich, have had endless appeal in culture but they’re often observed from the same spot. They’re usually set among a gaggle of overly paid, overly macho traders – either showing the extent of their dangerous greed like in The Wolf of Wall Street or how to punish them for it like in The Big Short.

Cleaning Up feels like an attempt to change this. Sam (Sheridan Smith) is a cleaner at Canary Wharf, a mother of two, and an online gambling addict. She eavesdrops on a trader (Ben Bailey Smith) who's told an illegal stock market tip and invests thousands.

Drowning in debt from the kids, her separation, and her gambling addiction, Sam sees an opportunity to raise some serious cash via insider trading. It’s easy to hate stockbrokers for playing with millions like it’s monopoly money, but what if a cleaner does it?

Sam rarely takes a breather. If she’s not dropping off the kids to school, she’s seeing her soon to be ex-husband about divorce settlements; if she’s not scrubbing the windows of Canary Wharf, she’s cleaning a posh house; and her spare minutes are spent fluttering on a virtual roulette wheel from her phone – all while abundant debts try to knock her over at every opportunity.

Considering what life’s throwing at her, we want Sam to succeed in this blatantly illegal and unethical activity. She’s like Robin Hood, only she’s taking most of the money for herself.

Sam’s a deflector, refusing to let anyone take her down or dig inside her. And that attitude is infused with a kindness, most often toward her own children. After warning her 15 year old daughter Alice (Kristy Philips) about seeing her 17 year old boyfriend, Sam hilariously states: ‘if he touches you, I’ll chop his bloody willy off!’. Sheridan Smith suits that character perfectly, using her trademark vivaciousness and finding it in Sam. It’s hard to picture anybody else playing her.

Writer Mark Marlow clashes different genres together without making the story feel like a mess. It’s mostly a social drama, showing the nauseous contrast between the cleaners and who they’re cleaning for. We rarely see the traders themselves, only what they’ve left behind to be cleared away.

But there are plenty of funny moments too, especially in the friendship between Sam and Jess as well as Sam’s clueless millennial lodger (Robert Emms) who becomes an unknowing aid to her plight. The story eventually slides into a heist movie by the end, sparkling with tense and playful thrills.

Episode one of Cleaning Up is good fun, and promises more to come. It’s hard to say whether Marlow will edge more towards the realism of Sam’s situation or the genre thrills of money and secret microphones. But regardless, Sam’s struggles pose an uncomfortable question: if we had her brains and her desperation, would we do the same?

Read our interview with Sheridan Smith here

Cleaning Up airs on Wednesdays at 9pm on ITV