  Nonlinear field model of extremal space-time film is considered. Its
space-localized solution in toroidal coordinates with periodic dependence in
time is investigated. A field configuration having a form of the twisted
lightlike soliton moving along the ring is considered. An iterative algorithm
for obtaining the solution in the form of formal power series in one toroidal
variable is proposed. It is discovered that the time dependence in the toroidal
solution has a deeply embedded character. Thus the full energy and angular
momentum of the solution converge at space infinity.
