What happens when meld into stone is cast through a familiar's touch?

Question

Meld into stone is a touch-range spell that melds the caster with the stone that he or she touches for the duration of the spell. When the spell ends, the caster exits the stone at the place entered. (See Can the Meld Into Stone spell be cast on someone else? for related.)

One way to deliver touch-range spells is through the touch of one's familiar.

What would happen when a caster delivers a meld with stone spell through the touch of their familiar?

I can imagine three possibilities, none of which seem very appealing:

1. The familiar touches and melds with the stone. Nothing happens to the caster.

2. The familiar touches the stone. You (the caster) meld with the stone at the place that the familiar touched, assuming other requirements are met (notably, 100 foot maximum distance between you and the familiar.) At the time that the spell ends, you return to the exact place that you were when you cast the spell, rather than adjacent to the wall you entered.

3. The familiar touches the stone. You meld with the stone at the point of the familiar's touch. When the spell ends, you exit the stone at the location that the familiar occupied at the time that the spell was cast.

Of course, there may be some other possibilities I've missed.

A few other situations seem related. One is casting plane shift through the touch of a familiar. Another is casting meld with stone with the distant spell metamagic.

Answer 1

This is really going to be up to the DM, but Option 1 is probably the most reasonable outcome.

There are often weird corner-case interactions when you start combining spell effects or class features from different classes. Honestly, it's to the credit of the developers that it happens as little as it does!

Spells generally assume that the "you" who is doing things in the spell description (like, say, touching a stone surface) is the same "you" that cast the spell, which is not always true when you start using a familiar. As players and DMs, we'll have to interpret which entity each "you" is referring to when we hit this particular situation.

While we are not obliged to assume that all "you"s are identical, it seems absurd to come to the conclusion that the line "you step into the stone at a point you can touch" should refer to two different "you"s. Since your familiar is the one who touches the surface, it's reasonable to rule that the familiar is the one that melds into the stone.

That fits the narrative of what's happening in the game world and does not lead us to the conclusion that the wizard will teleport across the room and possibly through doors and walls before the spell effect occurs.

Answer 2

Option 1.

From the Find Familiar spell:

Finally, when you Cast a Spell with a range of touch, your familiar can deliver the spell as if it had cast the spell.

Since the familiar is effectively the one casting the spell, they are the one who melds into the stone.

Keep in mind also, spells only do what they say they do. Allowing a meld into stone spell to effectively act like a teleport spell via a familiar would be well outside of both the stated purpose and rules of the spell.