Plugin lookup on second entity

CRM2016

I have a custom entity new_Headers which has a lookup to a custom entity new_originatingaccounts

The lookup field on new_headers is new_oaccountid

I an trying to retrieve the value from new_originatingaccounts for the field new_sun

my code below is not returning any record although I know the record exists

                        Try
                            ' Need to Lookup SUN
                            Dim strSUN As String = String.Empty
                            If entity.Contains("new_oaccountid") Then
                                Dim serviceFactory As IOrganizationServiceFactory =
                                        DirectCast(serviceProvider.GetService(GetType(IOrganizationServiceFactory)),
                                                   IOrganizationServiceFactory)
                                Dim service As IOrganizationService = Nothing
                                service = serviceFactory.CreateOrganizationService(context.UserId)
                                Dim req As New RetrieveRequest()
                                req.ColumnSet = New ColumnSet(New String() {"new_sun"})
                                req.Target = New EntityReference("new_originatingaccounts",
                                                                 DirectCast(entity.Attributes("new_originatingaccountsId"),
                                                                            EntityReference).Id)
                                Dim resp As RetrieveResponse
                                resp = service.Execute(req)
                                strSUN = DirectCast(resp.Entity.Attributes("new_sun"), String)
                            End If
                        Catch ex As Exception
                            Throw New InvalidPluginExecutionException("Error looking up SUN  - " & ex.Message.ToString)
                        End Try

Dont ask me .. i dont know