The West blames jihadist radicals, the Kremlin is searching for a Ukraine connection and Moscow is reeling. Russia's deadliest terror attack in nearly two decades follows the same modus operandi as the 2015 Bataclan concert hall massacre in Paris.
We ask about Friday night's bloodbath, why Moscow was targeted, the four alleged gunmen among the 11 currently in custody and the claim of responsibility by the Central Asia-based militants of IS-K.
As countries like France raise their terror alert levels, we ask about Vladimir Putin's next move. How caught off guard was he? And how will the Russian president respond to the grief and outcry?
Produced by Alessandro Xenos, Rebecca Gnignati and Juliette Brown.
