Tomorrow in the Battle Think on Me by Javier Marías.
Javier Marias builds a novel of infidelity around a man burdened by a terrible secret. Concealment becomes more than a plot device: it changes the terms on which people can know one another.
Read it for the relation between knowledge and obligation. The discussion begins with what a person owes others once he knows something that could alter their lives.
Edition note: The cover shown is the Vintage paperback (ISBN 9780307950758). The Apple Books option is the English ebook (ISBN 9780307951069). Both use Margaret Jull Costa's translation.
