A long time ago, Arumugam receives a wooden box as a gift from an anonymous Englishman for his kindness. Upon inspecting the box further in his house, Arumugam discovers a precious pink diamond. With no intention of selling the diamond, he and his piano-maker friend designed and built a custom-made piano that has a secret compartment that can only be unlocked by playing a unique tune. He splits the tune into four and teaches each tune to his four children separately. Arumugam later has Alzheimer`s disease and forgets about the piano`s secret, but mysterious figures find out the piano`s secret and goes after the family for the diamond.
