Abstract: A method and apparatus for recovering energy from a fossil resource that contains organic matter together with mineral material such as oil shale, coal. oil sand, etc., wherein a hydroretort and a gasifier are interconnected and are utilized in such a way as to have the hydroretort serve as the vessel for pyrolizing the resource by direct contact with hot syngas produced in said gasifier in order to extract oil from the resource while co-producing a residual mineral laden with carbon and some hydrocarbons. This residual mineral is fed from said hydroretort to said gasifier via a lockhopper and by means of oxygen and steam injected into the gasifier, the carbon and the hydrocarbons are converted to a hot syngas and the mineral matter converted to a molten slag which is cooled to a non-leaching substance.