As the rich harmonies of the cello and violin filled the lantern-lit cabin, Stephen Maturin – his fingers knowing the notes of their favourite adagio back to front by now – allowed his mind to wander freely.

The path of a person's life was so fickle and uncertain, he mused languidly, and the smallest things could have the largest of consequences. When picking up his violin, Jack had earlier mentioned the concert that had first introduced them to one another, and the tall, hefty captain had roared with merry laughter as he recalled their initial mutual dislike.

What if that had been it, Stephen suddenly wondered to himself. What if that had been the end of their dealings with one another? What if Jack had not received his promotion and, full of amiable wishes, sought him out? His life would be so completely different!

'Ha! I should be dead of starvation, sure,' he thought wryly, recalling the penniless and stranded figure he had been back then.

Without that fateful meeting, Stephen reflected, he would not have his current position as ship's surgeon, he would not have his other, more secret, work. And there would be no Jack Aubrey.

The relationship between the two was the most unlikely of friendships, truly, for they were different in almost every aspect. Jack was tall, broad and hefty; a striking figure in his immaculate uniform. He was constantly tactless, unsubtle, clumsy with words (those dreadful puns!) and too honest and trusting for his own good. However, for all that he was a genius at sea, a mathematician of incredible ability, a good and firm officer; brave as a lion, generous and kind-hearted to a fault.

Stephen on the other hand - small, sparse and untidy - was an intellectual. He was well-educated, incredibly erudite, with a host of languages at his command; a veritable encyclopaedia of knowledge on the natural world, human anatomy and of classic literature. He was sarcastic, sharp-tongued when ill-humoured, suspicious, secretive and untrusting – although he considered this more than justifiable given his particular profession!

Strange that two such men should grow to be so incredibly devoted to one another, yet that was what had happened. Their initial dislike had thawed into a strong and binding friendship, leaving the two closer than any brothers could possibly have been; each of them more than willing to lay down their life for the other if it was needed.

Stephen could not imagine life without Jack now. He simply could not imagine not hearing that hearty laugh, not cringing at those dreadful puns, or not having to ask for clarification at some obscure nautical term. Without Jack, there would be no one to lighten his soul; keeping him from the darkness which sometimes threatened to consume him. There would be no exquisite duets in the Captain's cabin after supper of an evening. Life would be infinitely duller and emptier!

Yes, fate did seem to link people's lives in strange ways...

'But thank God it had,' thought Stephen with a smile; his unusual blue eyes lighting up with pleasure as the duet reached its final crescendo. 'Thank God it had!'