Tom McCarthy’s most mainstream movie yet is an old-fashioned story about the old-fashioned way of pursuing journalism – swapping the armchair for the streets in the quest for truth, and nurturing the qualities of tenacity, maturity, research and rigour.

The newsroom explored in Spotlight is an increasingly endangered space, as is this kind of long-term journalism that requires reservoirs of patience and resources. Yet, Spotlight doesn’t set up false binaries between print and new media, nor does it treat its reporters as superheroes with notebooks. McCarthy’s no-frills approach and classic shot and reverse-shot storytelling often nudges Spotlight into the television movie zone, but there is no mistaking what is at work here: the good fight to tell a story the way it needs to be told.

The deftly performed and gripping Oscar-nominated production shines a torch on The Boston Globe newspaper’s investigation into a cover-up of sexual abuse by Catholic priests in the 2000s, apart from highlighting McCarthy’s achievement in the process. The filmmaker behind The Station Agent, Win-Win and The Visitor has a reputation for directness, nuance, and quiet power that gradually builds up through observation. That’s also the case with Spotlight, named after the paper’s investigative journalism section that speaks to power from a small room in the innards of the institution.

Written by McCarthy and Josh Singer (West Wing, The Fifth Estate), the 128-minute screenplay traces the beginnings of the Globe’s coverage of one of the biggest scandals facing the Catholic Church. Several priests have been abusing young boys and girls over the years, but the crimes have neither come to public attention nor have attracted prosecution or even censure from the Church. The four-member Spotlight team at the Globe, headed by Walter Robinson (Michael Keaton) and including Mike (Mark Ruffalo), Sacha (Rachel McAdams and Matt (Brian D’arcy James), has also passed over reports of complaints against priests in other sections of the newspaper. It takes a new editor, Marty (Liev Schreiber), to realise the value of the story. Marty is an outsider and a non-Catholic and therefore impervious to the social and political networks that run the city. When the Archbishop has a veiled conversation with him about the potential damage the expose could cause, Marty barely blinks.

The attack on the Church’s duplicity is similarly mounted with clarity and minimal emotion. It involves research and interviews but, most of all, empathy. Sacha meets the head of a coalition of sexual abuse survivors, while Mike tackles the maverick lawyer (Stanley Tucci) who is representing some of the victims. Mike, beautifully played by Ruffalo as a clenched-jaw dogged type, is the closest this movie gets to paying homage to the classic truth-seeking journalist stereotype best presented by All The President’s Men (1976).

When Mike loudly demands that the story be run in the next day’s paper rather than go through another round of edits, Walter looks at him in shock, as will viewers who didn’t anticipate the sudden shift towards stridency in a screenplay that eschews the death-knell feature of the truth-seeking movie.

Mike’s outburst is an exception to the rule that governs Spotlight. Its victories are incremental and its anger against a system that wilfully hid the terrible crimes is present but rarely allowed to manipulate the narrative. The tone is best personified by Keaton’s cool-headed burgher editor who works behind the scenes, using his old-boy connections and familiarity with the town’s ways to come closer to the truth. There isn’t the equivalent of the brilliant climax of All The President’s Men, in which the sound of typing resembles a firing squad. The glories of The Boston Globe reporters are hard-earned, as is respect for McCarthy’s insistence on mounting an attack on the Church’s suppression with the minimum of fuss.