When a conviction is based entirely on circumstantial evidence, all necessary circumstances proved must be consistent with guilt and inconsistent with innocence and must exclude every reasonable hypothesis of innocence. See Bishop v. Commonwealth, 227 Va. 164, 169, 313 S.E.2d 390, 393 (1984). "The circumstances of motive, time, place, means, and conduct must all concur to form an unbroken chain which link the defendant to the crime beyond a reasonable doubt." Id. In Collins v. Commonwealth, 13 Va. App. 177, 409 S.E.2d 175 (1991), a police officer drove his patrol car into a dimly lit parking lot and stopped approximately thirty feet behind Collins, who was sitting in a parked vehicle. When Collins exited the car, the officer saw him make "a throwing motion under the vehicle with his right arm." Id. at 178, 409 S.E.2d at 175. The officer immediately approached the car, shined his flashlight underneath the car and found a plastic baggie containing 14 smaller baggies of a white substance. There was nothing else under the car. We held that the evidence was sufficient to prove that the defendant possessed the cocaine and had thrown it under the car. We relied primarily on the reasonableness of the fact finder's inferences stemming from the evidence presented and observed, the court could have found that the defendant was merely off balance as he exited the car, or that he slipped and was attempting to catch himself. But the court did not so find. Instead, the court found that the defendant in fact threw drugs under the vehicle and that finding is binding on us, unless it is incredible or plainly wrong. It is neither under the facts in this record. The trial court was not unmindful of the defendant's argument that the cocaine might have already been under his car. The judge discounted this possibility, observing that the cocaine was "something of significant value and not something that one is likely to have abandoned or carelessly left in the area there." 13 Va. App. at 179-180, 409 S.E.2d at 176