Be careful what you wish for. Even three thousand years ago, humans must have realised that. But no, when his life is saved by being washed up on the beach at home, what does King Idomeneo do but make a rash promise to the Sea God for saving him. Does he not listen to the myths and legends?

In the English Touring Opera production of Mozart’s opera, directed by James Conway, the anguish of the king is powerfully conveyed by Christopher Turner. The inevitable happens, and the first person to find Idomeneo is his son, Idamante – only the promise was to sacrifice that first person to the Sea God. Oops!

Then there is the equally inevitable love triangle. As this is taking place after the Trojan War, Crete is full of displaced persons and prisoners. There’s Elettra, Idamante’s current girlfriend  - yes, her, better known as Electra – and the Trojan princess Ilia, who has been released from prison and who has fallen for Idamante. She has made an impression on Idamante, who releases the Trojan prisoners – all wearing green triangles on their breasts – for her sake.

All this takes place on Frankie Bradshaw’s diagonal set, with a monumental doorway to one side and stone walls which slide together to create a low wall between the town and the beach. Rory Beaton bathes it mainly in warm red-toned light, though storms are lit in harsh blue-violet.

Catherine Carby as Idamante is sometimes overwhelmed by the orchestra – she is totally overwhelmed with confusion when Idomeneo rejects his son. She catches Idamante’s youth and enthusiasm, verging on the impetuous in his dealings with the two girls in his life.

Elettra (Paula Sides) is the more hard-edged of the girls, Ilia (Galina Averina) coming over as warmer and softer. Their clothes contain a foresight of the eventual outcome; Ilia’s greenish garb co-ordinates better with the blue hues worn by Idamante and Idomeneo than Elettra’s mauve.

The tension as Turner faces his decisions is palpable. His first thought is to send his son off with Elettra to regain her kingdom – if he dies in the attempt, that’s no great mischief. Then, he is almost undone by Ilia’s warm embrace as her ‘new’ father. The departure being delayed by a storm, he realises he must appease the Sea God – and sacrifice his son. Averina is heartrending in Ilia’s aria, offering to die in Idamante’s place.

When The Voice of Doom intervenes and suggests a suitable sacrifice would be for Idomeneo to abdicate in favour of his son, Elettra, seeing her hopes and dreams destroyed, tips over the edge. Sides’ ability to sing when struggling with her arms held behind her is impressive. She is held by Arbace, Idomeneo’s friend, factotum and High Priest, sung by John-Colyn Gyeantey.

The chorus has a major part in this opera, filling in the story, responding to developments, and is particularly powerful in the scene with Idomeneo and the High Priest. Jonathan Peter Kenny and the orchestra complete this satisfying performance.