The Other Woman

 is the eighteenth book in the Gabriel Allon series.

Prologue
An unidentified child arrives in Moscow by air and is taken by limousine to an apartment in an older section of the city.

Night Train to Vienna
Gabriel Allon is in Vienna, leading an operation to bring Konstantin Kirov (code named Heathcliff), a Russian SVR operative who been co-opted by the office years earlier, in to safety because his life was in danger. Gabriel walks without his protective guard, Oren, past the place where his first wife, Leah, and son, Dani, were the targets of a terrorist bomb and arrives at the safe house where Eli Lavon is supervising the surveillance of Kirov.

Kirov arrives at a rail station and is followed by Christopher Keller and by Mikhail Abramov.

Commentary

 * Headlines in the synopsis are from the book.
 * Kim Philby is cited as a reference character because he does not appear in the present.
 * Oren appears for the first time.
 * Oded and Mordecai do not appear.
 * Dina Sarid is only referenced.