Dr. Wu was essentially the only character to return in Jurassic World from the original Jurassic Park, at least if you discount a cameo from Ian Malcolm's book, and multiple references to and images of John Hammond. And he did an admirable job walking the line between simple InGen employee and mad scientist. At least until the end, where he seemingly goes full crazy. It's at that point, towards the end of the film, where there are references to a nefarious side project involving Dr. Wu, which is clearly a setup for a future film. So something any sequel to Jurassic World is going to need to do is pay off that setup. It's all very reminiscent of Nedry's little side business in Jurassic Park, proving once again that no storyline is too miniscule to recycle. It is, however, an interesting one.