Algernon Blackwood 
Bright Messenger [PDF ebook] 

Edward Fillery is the child of a brief but passionate liaison between an engineer and a strangely beautiful peasant girl. Blessed with special insight and with a 'primal quality’ in his blood, Edward becomes a doctor, helping and healing those with distressing psychological illnesses. When he hears of an unusual case in Switzerland he is intrigued and moved. The young male patient, apparently born of a 'magical experiment’, is a man of mystical tendencies, a worshipper of natural forces. And when he sees a portrait of the patient, there is a brief, indefinable spark of recognition…