Jade and Erk: Into the Crystalline Caverns

Jade and Erk are extraordinary teens in a futuristic city on another planet in the far flung future. Jade is the fledgling daughter of the city's top agent and hero, while Erk is her adopted non-human brother abandoned by one of the planet's native tribes. The two find themselves caught in the crosshairs of a violent gang, which leads them into an ancient underground cave system outside of the city.