Renowned record-breaking open water swimmer and author Lynne Cox will visit Eagle Harbor Book Company to discuss her new book “Swimming in the Sink: An Episode of the Heart” at 3 p.m. Sunday, Sept. 25.

Cox is no stranger to facing challenges and breaking boundaries. In 1987 she crossed the Bering Strait — when the Iron Curtain was still up. In 2003 she swam more than a mile in the freezing waters of Antarctica.

In “Swimming in the Sink” Cox documents her most recent challenges — the death of both parents and a diagnosis of broken heart syndrome. This is a powerful book about super athleticism and human frailty, about invincibility and the sudden (mind-altering) repercussions of illness and about the triumph of spirit, surrender and love.

Cox is an elite athlete who broke many world records, among them swimming the English Channel at 15, being the first woman to swim across Cook Strait (18 miles) and being the first to swim in Antarctica in 32-degree water for 25 minutes, all without a wetsuit.

“Swimming in the Sink” begins at a laboratory at the University of London, with Cox’s hand in ice water, hooked up to thermocouples and probes, with three scientists trying to make sense of her extraordinary capabilities. The test results paved the way for new medical and life-saving practices.

As an athlete, Cox put her heart into everything she’d ever accomplished.

In the midst of becoming the embodiment of a supreme endurance athlete, Cox took care of her elderly parents, both of whom passed away in quick succession, followed by the death of her beloved Labrador retriever, leaving Lynne in shock from loss and loneliness and soon suffering from the debilitating effects of a broken heart.

On the edge of a precipice, Cox was diagnosed with atrial fibrillation.

As the prognosis went from bad to worse, Cox was in fear of living out a lesser life as an invalid with a pacemaker and a defibrillator and the real possibility of her own death was before her.

Cox writes of her full surrender to her increasing physical frailty, to her illness, her treatment and her slow pull toward recovery.

In “Swimming in the Sink” readers see Cox finding her way, writing about her transformative journey back toward health and slowly moving toward the one aspect of her life that meant everything to her freedom; mastery; transcendence back to open waters, and the surprise that she never saw coming: falling in love.

Eagle Harbor Book Company is located at 157 Winslow Way East. Visit www.eagleharborbooks.com to learn more about author events.