The underworld_bl.exe file you have requested: Mods / Multiplayer / Underworld Bloodline / -Releases / Underworld Bloodline - 29.53mb is not available. Perhaps try browsing all files for the game Half-Life and upload any files you want to share or are missing. This is the only information we could locate:
A new halflife mod made by the same people who made the "They Hunger" series. UB features two races, the Vampires, and the Lycans. Each race has thier own abilites, like being able to jump extremely high, or running very fast, you do the math. The mod has a fairly interesting gametype where the main goal is to capture a hybrid lycan/human as the lycan side, but, the vampires can kill the hybrid, or capture it. Its worth the download to check it out.