Their relationship began with a contract, and may also end on the day the contract expires. Group head Shen Bing and security assistant Jiang Hu meet through work; one is calm and restrained, while the other looks casual, yet they become each other's most tacit partners through day-and-night companionship. Those unspoken cares quietly change the original boundaries. As the agreed deadline approaches, will they return to their initial positions, or entrust the next leg of the journey to each other?