Evaporation; Not Just for Liquids!

I've been trying to put my flat together for a couple weeks now.  And, honestly, I've been doing a pretty fair job.  A couple of things have been on hold, though, because the IKEA loft bed that I bought, with attached desk, under the loft, didn't have screws with the desk part.  Or, at least, I couldn't find any.  It's possible, I suppose, that I tossed the screws when I got rid of the packaging.  But, I did try and locate them before I decluttered.  Never saw them.  Nor a hint of them.  So I made a trip down South (IKEA is at the extreme South end of the valley, and I'm at the North) to get them.  No problem.  The attendant went straight back to the spare parts area to locate the missing bits.  And she found them.... well, most of them.  She couldn't locate one screw, of which I needed two.  So so put in a request and had them shipped to my house directly.  That was back on Thursday of last week.  Fast forward to this Friday.  The screws appeared in my postbox!  Yeay!  Now I can complete my desk, right? 

HA!

I go up to my flat, open the package, take the screws out and put them with the other screws, in a Ziploc plastic baggie.  I vividly remember doing this.  I set them down and went to find the screwdriver.  Come back, get the desk bits out..... and the screws have evaporated!  *poof*  Gone.  Seriously.  I took the flat apart looking for them.  I put the flat back together, looking for them.  I've searched for TWO SOLID DAYS for them.  I. Cannot. Find. These. Screws.  (Yes, yes, I know I've always had a few screws loose.  But these ones are missing all together!)

Lois said she'd come help me search on Monday.  Seriously, I really doubt she'll find them.  I've searched every surface, every drawer, every box.  I've even checked the rubbish.  TWICE!  I've looked in all the obvious spots, and started looking in some really strange ones; the dishwasher, the fridge, the bathroom cupboards.... just on the off chance that I wasn't paying attention to what was in my hands.  I have no idea what has happened to these screws!  It's making me crazy.  And, on top of that, it's keeping me from finishing getting my things settled.  I can't set up my office til I get the desk squared away!