She obeyed the will: flying from Oman to London, then taking another three and-a-half hours by bus to reach Pentland Firth and the Scottish isle of Floasa.

Like its sister Stroma, the lure of the mainland and hardship of living on such a barren, rain-battered rock had sucked the youth from the isle. Two wizened men and a sullen crone were left to welcome Hasina Irshad from the fishing boat; they took her by donkey trap to the cottage that had been her father’s.

Hasina waved to her driver, then dashed to the gas stove and changed out of her wet clothes. Looking around the humble shack, the new diesel generator, the specimen cases and reference books, Hasina could not fathom what had taken the geology professor of Sultan Qaboos Uni to this spec off the coast of Scotland.

Her iPhone chimed. Time to find Mecca, to make ablutions and perform Ṣalāt. Starting the GPS app, she opened the water tap.

Thin, pinkish slime spattered her arm and face as the tap coughed violently. Something yellow writhed in the gush.