Tonic is a Bengali family drama starring Dev as Tonic, Paran Bandyopadhyay as Jaladhar Sen, and Shakuntala Barua as Uma Sen.

Jaladhar, a 75-year-old retired man, lives with his wife and family but feels restricted by his overprotective son. When his son refuses to celebrate his parents’ wedding anniversary grandly, Jaladhar and his wife decide to fulfil their dream of travelling abroad. They meet Tonic, a cheerful travel agent who helps them rediscover the joy of living. Together, they embark on an adventurous trip to Darjeeling, where Jaladhar overcomes his fears and enjoys life again.