We feed Morgan some kind of poison, which makes her ill. And when Dad is in the emergency room, that's when the party begins!
Let me get this stright, you would poison your sister to surprise your father?
Now if Morgan goes south, you know, if she croaks, it will put a damper on the whole party. That's why we will have... Horsey Rides! See, me on the horsey, (let's call him Pete) on Pete having fun, joy, merriment. Any questions?