According to Victor Hedman's agent (via the Tampa Bay Times), the Lightning defenseman has signed with Barys Astana of the KHL in Russia. 

Hedman's agent Peter Wallen telling Damien Cristodero the team was looking to add a defenseman, and Hedman has agreed to fill that spot. 

The NHL is currently in a lockout as both sides are reportedly still far apart from agreeing to a new collective bargaining agreement.