Heartseeker is an enchanted composite longbow +3. It has a +4 THAC0 bonus and it has the same +2 bonus to damage as a normal composite longbow. The bow weighs 7 lbs. and has a speed factor of 4. The combat ability of this bow is that THAC0 can be increased with an additional 7 points for nine seconds, in which three arrows can be shot from this bow. This item appears in Baldur's Gate II: Shadows of Amn and Baldur's Gate II: Enhanced Edition.
Legends say that craftsman Pinn O'Reffen fashioned this bow from the heart of a Treant, though how he came to possess such material is unknown. He certainly did not anticipate the enchantment within, magic that makes the archer's aim almost infallible for a short period every day. Pinn claimed his skill was responsible, but it is more likely that some aspect of the soul of the Treant is still within the wood. This bow requires a strength of 18 to use.