As is to be expected from a writer whose debut novel so successfully broke with convention (2009's Wizard Bakery was the first South Korean young-adult novel to employ magic as a major plot device), The Old Woman With The Knife is a thriller with a difference. Who isn't fascinated by what might become of a hired assassin lucky enough to reach retirement age?

Award-winning Gu Byeong-mo (translated here by Chi-Young Kim) delivers unexpected touches of tenderness within the brutal, exacting world of 'disease control'. Hornclaw may look like a mild-mannered grandma, but is actually an experienced killer trying to retain an iron grip on her reputation as a founding member of her firm. The march of time is against her, as is a cocky young upstart Bullfight who delights in trying to get under her skin. Unfolding at a meditative pace, this thriller is unusual in quietly sucking the reader in, all the better to twist a tension-laden knife or undercut complacency with an emotional moment. Complexities reveal themselves in good time and are well-balanced by the intriguing premise and characters.

The people Hornclaw is sent to assassinate are described as vermin; individuals who have slowly morphed from human beings into rats or insects, helping to paint our protagonist as an anti-hero who we are happy to stick with as she carries out her assignments. Pretending to be an old busybody might be an impeccable disguise, but once she's been rumbled, her age can surely only work against her … ?

Both the subject and wry, black humour are reminiscent of The Godmother by Hannelore Cayre, while it deserves those comparisons to Leïla Slimani's Lullaby too. It is a delight to root for Hornclaw as she contemplates her place in the world, even when starkly reminded of the intricacies of her profession.

Gu Byeong-mo: The Old Woman With The Knife is out now published by Canongate.