The truth never conclusively surfaces in Doubt, John Patrick Shanley’s clever 2004 play that won the Pulitzer Prize and eight Tony Awards and is now revived in a shadowy, breathlessly tense production by Che Walker at the Southwark Playhouse. The piece is set in 1964 in a small convent school in the Bronx. Morality is in flux. Kennedy, the first Roman Catholic president, was assassinated the previous year. The conservative wing of the church is outraged by the new informality proposed by Vatican 2. That certainly goes for Sister Aloysius (Stella Gonet), the redoubtably reactionary head of the school whom we first hear riding roughshod over the idealistic teaching methods of the young, painfully sincere and sweet-natured Sister James (spot on Clare Latham). Ballpoint pens, secular songs in the Christmas pageant (Frosty the Snowman is a heretic at the gates) are as anathema to her as enthusing pupils through theatrics in the classroom. “Look at you, you’d trade anything for a warm look,” she jeers at Sister James. Her own philosophy is that in order to lead their charges to the path to righteousness, the nuns have to be feared.

All of which sets her on a collision course with Father Brendan Flynn (Jonathan Chambers), the charismatic Irish priest and school baseball coach who represents the post-Vatican 2 spirit in his desire to break down the idea of the clergy as remote moral exemplars. His sermon on doubt (“Doubt can be a bond as powerful and sustaining as certainty”) stokes her suspicions. When the junior nun confides that Flynn has befriended a twelve year old boy, the only black pupil in the school, and had a meeting alone with him, these are intensified. The scene is set for a battle of will that feels all the like fierce combat here, with the audience disposed round a confrontational strip of stained-glass floor in P J McEvoy’s eloquently minimalist design.

Stella Gonet brings a merciless caustic implacability to the nun’s mission to expose Flynn. You might think her a refugee from Arthur Miller’s Crucible if it weren’t for the fact that witches don’t exist whereas child-abusing Catholic priests demonstrably do. In the light of all the recent scandals, a part of you admires Sister Aloysius for trying to the better of a patriarchal hierarchy where the word of priests is always conveniently given precedence over that of nuns. One can only imagine how differently the situation would have been handled in most schools in the period. A conspiracy, presumably, to brand whistle-blowing Sister James as delusional.