Seek & Find Order: My wife has flown to her native U.K. with the children without my knowledge or consent. Can I start abduction proceedings to get my children back to Israel even though I am not sure where they are staying in the U.K. but I do know my mother-in-law's address and they are probably there?

Yes ! Hague Convention proceedings for the children's return can be started in the U.K. on the basis that the children have been wrongfully removed from Israel , and are being wrongfully retained in the U.K, presumably at their maternal grandmother's home. The application can include a request for a "seek and find" order to locate the children. If the children are not there when service of the appropriate orders /summons is attempted at the maternal grandmother's home, she can be arrested if she refuses to disclose their whereabouts.