Competent if slightly stodgy (and now rather dated) British B-movie. The plot centres around a child critically ill in hospital who needs a blood transfusion to save her life. Unfortunately she has a rare blood group, so Scotland yard are called in to track down possible donors. This is used as a framework for a collection of little stories about life in London ca 1950 rather in the style of "The Blue Lamp". Jack Warner and Sid James as a boxing manager (who could be a decent character actor when he tried) do a reasonable job at keeping the plot afloat. Now mainly of interest as a social document.