Project Arts Centre, Dublin:The two productions within Rough Magic's AIB Seeds showcase provide a tale of two cities, and once again it is the best of times and the worst of times. The New York in Christopher Shinn's ominously titled Dying Cityis the stunned and dispirited centre of 9/11 and everything after. The 1980s London of Caryl Churchill's exuberant financial satire is a hive of capitalism and cannibalism, where greed is good, there's no such thing as society and the market will presently eat itself.

As director of Shinn’s 2006 play, Des Kennedy certainly has less fun. A sombre and tortuous meditation on love and war, it is not the first time Shinn has used identical twin brothers as a device to explore duality and truth. Asked whether she has personal effects to remind her of her husband, a deceased soldier, the sullen therapist Kelly looks into the face of his brother, Peter, and replies, “I have other things”. More an actor’s showcase than a director’s, the play is all exposition and flashback, a slow unfurling of detail and psychology that offers its greatest challenge to Paul Mallon. Slipping between the roles of Peter (narcissistic, tank-top wearing, gay, emotional) and Craig (intellectual, lumber-shirt wearing, aggressive, reserved), his polarised figures are easily distinguished, but harder to believe in. Gemma Mae Halligan’s damped-down emotions as Kelly are further muted by over-elaborate lights, and the production thickens the sense that the play is full of questions – about war and truth, personality and politics – but slow to initiate answers.

What did the 1980s give us? The answer, to judge from Aoife Spillane-Hinks’s ferociously entertaining production of

Serious Money

is: a fascinating portrait of lurid excess, a culture of engaged and sharp artistic wits and – it seems – the vast majority of her excellent cast. It’s unclear whether the energetic ensemble is revelatory because the material is so good, or if their verve makes the play seem so fresh and wicked.

Either way there’s thrilling, trading-floor amperage to the show, in which Alyson Cummins’s stock exchange set ensures a perfect balance between work and play. Churchill’s plot – a wild sleuth chase, engagingly pursued by Valerie O’Connor’s superb Scilla – guides us through the class turmoil and transnational love-in between Thatcherism and Reaganomics. In 1987, it was both a lampoon and a warning. Today it is a weirdly gleeful post-mortem, vicious and restless, in which rhyming couplets, multiple role-play and fleet-footed stagecraft find ingenuity in poverty. Certain polemics are a little late for their no-longer bloated targets, but in a gloomy time the show knows that there is still serious fun to be had and nothing left to lose.

Dying City

is at 6pm and

Serious Money

at 9pm until Saturday. Maria Elner’s new play,

The Door That Sings Bellini

, and Ciarán Fitzpatrick’s

The Rapture Index

, receive rehearsed readings at 1pm and 3pm tomorrow