Hydra is the sixth studio album by the Dutch symphonic metal band Within Temptation. It was released on January 31, 2014 in Europe and on February 4, 2014 in North America. The album contains guest appearances by metalcore singer Howard Jones (ex-Killswitch Engage), rapper Xzibit, classical-crossover/symphonic metal vocalist Tarja Turunen (ex-Nightwish) and alternative rock singer Dave Pirner (Soul Asylum). The first single, "Paradise (What About Us?)", was released on September 27, 2013, and featured Turunen as guest vocalist. The second single, "Dangerous", was released on December 20, in which Jones provided the male vocals.