As the summer of '69 reaches its zenith, U.S. Senator Ted Kennedy](/actor/jason-clarke) (D–MA) grapples with the heavy burden of his family's legacy, especially the memories of his brothers, John Kennedy and Robert Kennedy. During an impromptu chat with cousin Joe Gargan, he expresses a heartfelt wish to honor their memories by inviting the hardworking Boiler Room Girls, who played a crucial role in Bobby's presidential campaign, for a relaxing getaway on Martha's Vineyard. This leads him to a lively gathering at a cottage party on Chappaquiddick Island, where his attention is inevitably drawn to Mary Jo Kopechne.
As the evening progresses, Ted and Mary Jo take a carefree drive through the island, casually interacting with a police officer they encounter. However, their serene night takes a harrowing turn when Kennedy, momentarily distracted, drives off the Dike Bridge, crashing into the water below. In a frantic state, he escapes the submerged vehicle, frantically calling for Mary Jo, yet receives no reply.
In the aftermath, consumed by distress and turmoil, Kennedy seeks refuge in his hotel room, trying to calm himself with a soothing bath. Despite Gargan's](/actor/ed-helms) urgent pleas for action, he opts instead for solace from his father, oseph P. Kennedy Sr., who cryptically advises him to "alibi." As the night drags on, Kennedy's unease mounts, culminating in a crucial and ill-fated telephone call.
The following morning, the discovery of the submerged car by two fishermen sets off a police investigation that threatens to expose hidden truths. [Gargan and Paul Markham realize that Kennedy's failure to promptly report the incident could spell disaster and insist on taking responsibility. However, Ted remains paralyzed by indecision, caught between his moral compass and an urgent need for self-preservation.
As Markham's testimony reaches Chief Arena, Kennedy heads to his family’s prestigious estate in Hyannisport, believing he has effectively navigated the storm from his actions. Yet, his father's harsh criticism, along with the arrival of a damage control team led by Robert McNamara, quickly shatters this illusion. The harsh reality sets in as they frantically orchestrate a cover-up, working to ensure that the deceased is not subjected to further scrutiny and altering records to include an expired license through their influential connections.
Their elaborate strategy aims to shield Kennedy from legal repercussions while the public's attention shifts to the momentous Moon landing. In a misguided attempt to play the sympathy card, he appears at Kopechne's funeral with a neck brace, but this strategy backfires and turns the media against him.
Desperate to change the narrative, Kennedy's team recommends a televised address to the citizens of Massachusetts, leveraging the family’s significant political influence to navigate the impending court case without a trial – aware that anything he says could be used against him. Consequently, he ultimately pleads guilty to leaving the scene of an accident, receiving a minimal jail sentence of two months, which is promptly suspended due to his esteemed reputation.
As Gargan becomes increasingly disenchanted by Kennedy's manipulative tactics and dishonesty, he considers resigning from his role. However, still stung from criticism from the elder Kennedy, he is instructed to prepare a resignation speech, but told not to inform anyone of this plan.
In the days leading up to his address to the nation, crafted meticulously by Ted Sorensen to evoke sympathy, Gargan hands him a statement meant for his own use. Ironically, as Ted addresses the public, it is Gargan who holds the cue cards. The public's reaction is split, but a significant number indicate a willingness to support his reelection.
As the credits roll, we learn that Joseph Kennedy Sr. passed shortly after these events, while Gargan ultimately distanced himself from the family and Kennedy faced defeat in the 1980 Democratic presidential primaries, yet continued to serve in the U.S. Senate for four more decades, leaving a complicated legacy behind.
