async.waterfall([
  function1,  // returns Thing1
  (function () {
    return function (Thing1) {
      function2(Thing1, Obj1, Obj2, Obj3);
    };
  }()),  // uses Thing1 to create Thing2 but also requires a lot of other parameters to be passed to it.
  ], function (err, result) {
    if (err) {
      console.log('barf')
    }
    res.json(201, { thing1 : result.thing1, thing2 : result.thing2 })
  }
)