This book is focused on British readers. The Russian revolution is
cast as British colonial adventures with British officers helping the
whites in their doomed noble quest to restore democracy? monarchy?
something.

Beevor has access to soviet sources but instead relies nearly
exclusively on British correspondence and pro-white Russian witness
accounts. The atrocities of the reds are described with relish.  The
white cossack atrocities are added as a counterpoint to show the local
color.

October revolution is called a coup. February revolution is shown as
failed bid for democracy. The reds are portrayed from the outside as a
mass of infighting bloodthirsty predators taking over the country and
threatening to export the revolution to the whole world. Duplicitous
Churchill with his anti-bolshevik fervor, lying to parliament and
sending arms and troops to Russia and given aid to
counter-revolutionary forces in an attempt to crush the reds is given
plenty of space. 

This book is useful as a good as a contrast as official soviet
historiography, but to call it biased is an understatement.