When Twitter user @StewartL64 told Irish Twitter that he found a letter written by Séamus Heaney inside a second-hand book, the search for its recipient began.

The letter was found a number of years ago in a book Stewart had bought in Belfast. Addressed to a Miss Sophia Hillen, it was dated September 3 1973.

In the letter, the poet seems to be referring to a job opening in the field of Anglo-Irish literature at UCD. He appears to have been writing in response to a friend.

Eager to see the letter returned to its recipient, Stewart asked Irish Twitter to "do its thing".

Don't often ask for retweets but hoping Irish Twitter will do its thing. Years ago I found this letter from Seamus Heaney inside a 2nd hand book I bought in Belfast. I wonder if the owner would like it back? pic.twitter.com/Qax46RfVfp

— StewartL64 ❄️ (@StewartL64) July 3, 2018

Stewart’s tweet received almost 700 retweets and over 1,000 likes. The owner of the letter was found in mere hours and the letter was reunited with Sophia Hillan, whose name Heaney had misspelled at the time.

"I was applying for a lectureship at University College Dublin," Sophia told Hot Press regarding the content of the letter. "I was finishing my MA in English Literature at Queen's University Belfast. The year before, 1972, I had graduated in English Language and Literature and in final year, when I specialised in Anglo-Irish Literature, Séamus Heaney had been one of my tutors."

Sophia said that that year, Heaney left the university and was living in Wicklow. A few years later, when Sophia had married and settled in Dublin, she worked with him at Carysfort College where he was Head of English. "It was then that I got to know him and his wife Marie as friends."

Sophia said that Heaney was extremely encouraging in her career and supportive of both her academic and creative writings. "We remained correspondents and friends all through his life," she added.

So what would 1973 Sophia think of a stranger finding a letter the Nobel Prize winner sent her and seeking her out over social media only for the letter to go viral? “I think, though the internet and Twitter and all of social media was unheard of, I would not have been surprised that a letter from Seamus Heaney would one day be of great importance. He was, even then, highly regarded as a poet of exceptional ability.”