A man of average height, standing around 5'10", with a lean and somewhat wiry build. His once-dark hair is now speckled with gray, often unkempt and tousled, giving him a slightly disheveled appearance. His sharp, intelligent eyes are a deep brown. His face is gaunt and lined with worry. His nose is straight but slightly crooked and his mouth is often set in a tight, contemplative line. He wears an old, worn-out lab coat over a simple shirt and trousers.