okokok so I have a conundrum. 2 of my 4 players are trying to infiltrate a cult. To prove his loyalty, Zeno (necromancer) will clone and then 'kill' Syrus (Warlock). The main problem of this? They haven't started the clone yet and they're level 16. Basically, I need help coming up with a subplot that lasts like 128 days without it looking odd and the others catching on. Ask any questions you need to know but here's some details. 

-The cult are looking for their statue gods, and the party has a double agent in said cult that will tell them as soon as it as found. They've looked at 3/4 of the country where they know it's in. 

-the other two players do not know about the plan. 

-the Warlock's wife is with the party

-they've put me in a crummy juncture. Sir's ma'ams and oth'ers please help a s t r e s s e d teen out. 

You could try adding in a political subplot. Suppose they find out the location of the statue, but it's currently in the possession of a major political figure, or is even being held on display in a central government building. Assuming the cult doesn't have the means or numbers to simply steal the statue, they could try contacting a powerful connection within the government, possibly even a noble or politician that is secretly a member of the cult. However, given that it's complicated legal matter, this could involve various errands for political figures, working into the good graces of influential people, and just general waiting around, since the wheels of bureaucracy tend to move slowly.

Why not have the players try to find the statue gods themselves, quietly, and then revert to the plan to infiltrate the cult if the cult find them first?  They could use their many contacts (they're level 16 after all) to be on the lookout (BOLO) while they did something else in the meantime.

Well the clone-involved players can just not infiltirate the cult yet. The other players can try before that blindly. They can also use the time needed for the spell to develop to gather information and resources to help them fight the cult.

Timeskips typically, well, skip a bunch of time.  Usually what happens during a timeskip is the characters do their own side quests.  Training missions, visiting family and so on.  Then the timeskip ends with the players meeting back up to continue the main story.  In anime and manga, the timeskip is usually a story arc in its own right that runs parallel to the main story arc.  For d&d purposes, you could just have your players write up their timeskip adventures, advance them to level 17 and then jump right back into the main arc several months later, with them meeting back up again at their base, or a local tavern/guild or their mom's house or whatever.  The clone would then be complete and they'd set off to infiltrate the cult.

This could quite literally be done between sessions. If you want to do the timeskip in session, just let your players run around and do their own side quests or visit family for a couple of sessions.

Personally, though, I think that having them write up their timeskip adventures is a better idea.  Especially if they will cooperate with each other.  Even if they all go off in different directions though, it isn't going to matter to your main story arc if they just write them up.  

They will still end up meeting back up again to continue the main story arc.

This might not be what you're looking for but, wouldn't Feign Death be easier as you are running a scam to prove loyalty anyway?

Quote from Wtfdndad >>

This might not be what you're looking for but, wouldn't Feign Death be easier as you are running a scam to prove loyalty anyway?

I would guess the OPs players have chosen the clone route, so it would be kind of a d**k move to say "no you cant do that" without a reason.  Also the cult might have ways of knowing if the person is really dead or not.  

I know the OP doesn't say anything like this, but what if the cult burned all the dead people, or fed them to some demon or something?  Then it would be the actual character getting killed, not the characters clone.

Also, this is a cool use of a spell that the players might not get to use often.

Per the Clone spell, the actual character IS being killed. You better go read it.

I see what you mean.  I was thiking of comerhing else.  Although also consider players in my game to be "souls" rather than bodies.

The body is only shell thing and all of that.

I still see what you mean though and was thinking if a different spell.

EDITED - to make the post read better and my possition for clear.