The heart of a 900-year-old saint was stolen from a church in Ireland over the weekend, the AP reports.

The preserved heart of St. Laurence O’Toole, the patron saint of Dublin, has been on display at the Christ Church Cathedral in Dublin since the 13th century. It was stored in a heart-shaped wooden box and secured in a small, square iron cage on the wall of a chapel dedicated to his memory.

Sometime between Friday night and Saturday afternoon, someone cut through the bars and made off with the relic.

A spokeswoman for the church said the thieves ignored valuable gold chalices and candlesticks in the chapel. “It’s completely bizarre,” she told the Irish Examiner. “They didn’t touch anything else. They specifically targeted this…They wanted the heart of St Laurence O’Toole.”

According to Rev. Dermot Dunne, the cathedral’s dean, the heart has no economic value. “...but it is a priceless treasure that links our present foundation with its founding father,” he told Rev. Dunne has appealed for the safe return of the artifact.

Irish police are studying CCTV footage to help identify the thieves.

O’Toole was Dublin’s archbishop from 1162 to 1180. Pope Honorius III canonized O’Toole in 1225 because of a number of miracles that supposedly occurred at his original grave site. O’Toole’s heart was the last surviving part of his remains.