Stella Fregelius by H. Rider Haggard

Following a shipwreck Stella is preparing to die but is unexpectedly rescued. A love triangle of an unusual sort develops where an inventor of the mobile phone, back in 1900, who is engaged, becomes involved with a woman who has a passionate mystical influence on him. The story explores the nature of death and how we should look forward to it as being a great step to a greater world.