Bilingual book to learn Spanish

In bilibook-editions the text is displayed alternately sentence by sentence in both languages. In addition, some words are marked so that you can find them fast in the translation text.

This system helps you to maintain a comfortable reading flow. You do not have to read the entire translation to find a word translation.

The story: 
A young London hydraulic engineer comes to Sherlock Holmes and Dr. Watson because of his missing thumb, and explains what happend. He had accepted a job that brouhgt him disaster.