Taking place in and around the fictional N. Sanity Island, Crash Bandicoot 2 follows the adventures of the anthropomorphic bandicoot Crash. Crash is abducted by series villain Doctor Neo Cortex, who has seemingly turned over a new leaf and now wants to save the world. Crash is then thrust into several parts of N. Sanity Island in order to gather Crystals and allow Cortex to contain the power of the upcoming planetary alignment and keep the planet from being destroyed. Crash is joined by his sister Coco, who is suspicious of Cortex's true intentions, and partially by Doctor Nitrus Brio, who tries to persuade Crash to gather Gems instead of Crystals.
Source: Wikipedia, "Crash Bandicoot 2: Cortex Strikes Back," available under the CC-BY-SA License.