So I’ve been thinking about this lace repair caper, and reading the comments, and I think I should clarify a few things.
Not to indulge in false modesty (trust me, you can always count on me to be the last person to do that…!), but I swear on a stack of Elizabeth Zimmermann books that this was not as horrendous or as difficult as it may have looked. Honest. You want to see a really harrowing saga of lace repair, of insane courage in the face of utter self-inflicted carnage, take a look at the tale of S. Kate. Warning: not for the faint of heart or digestion.
The S. Kate story is in the archives of the Yarn Harlot’s blog, which at this writing is - not surprisingly - experiencing some bandwidth overload. So right now is not exactly the best time to look, but I’ll give you the links now for future reference. It’s worth waiting for, I assure you. The photographs are breathtaking. The original S.Kate posts are here and here, but for now you can also get a small glimpse of the episode as described on Rosie’s blog here.
I believe - I hope - I could, and would, have done the same if I’d had to. I thank my lucky stars and my lifeline that I haven’t had to - yet. Actually, let me be more precise. I do bless the lifeline, but in real life it wasn’t so much the lifeline that prevented total disaster in my case - more than anything else, it was the structure of this particular lace.
And now that I’ve gone back and looked at the S. Kate repair again, it comes to me that there is more structural similarity than I remembered between the two situations. Her problem was on a larger scale than mine, and her approach to solving it was more disciplined - but both cases feature a triangular lace figure built on a single foundation stitch, with lucky lateral limitation (say that three times fast) on the spread of the havoc.
Now. Let’s break this thing down.
I’m afraid a couple of the pictures I used to illustrate this yesterday were a bit misleading. Sure, I did mention that the lace is worked top-down, but were you supposed to stand on your heads to look at the pictures? Also, highlighting a negative fan figure in the middle of the blocked swatch instead of at its edge - um, that didn’t make much sense either. So please forget this picture…

… and think about this one instead:

Today I dry-pinned a section of The Red Blob in progress, to show you more precisely what I’m dealing with. (I did think about recreating the actual disaster so I could mock up the Before picture I failed to take… but I think we’ll let that slide for now. I’m a couple of rows beyond the new lifeline now, and I don’t want to pull it. Maybe if I’m feeling quixotic when I get to the same place in the current repeat. Maybe not.)

Here’s a closer view of the inverted negative fan on the needles:

And here it is again with the two critical spots marked:

Oh yeah - and that’s another good reason for not trying to reconstruct the crime. I don’t remember for sure which stitch it was that I dropped. I almost think it must have been the one on the right, though, because the one on the left wouldn’t have been nearly as hard to pick up. Either way - if you can’t imagine by looking at it exactly how such a stitch if dropped would ravel a whole series of stitches below it and to both sides - well, then, you have a higher tolerance than I for horror stories and gore. Follow the line of decreases and YOs downward from the stitch and see how interdependent they all are. Ack. Once they drop, it’s still possible to reconstruct the stitches, but it’s incredibly confusing because the YO strands twist around each other and I frankly get dizzy trying to figure out where to shove each twist as I’m rebuilding. To the right of the reconstituted stitch? to the left? What if the stitch below it was also supposed to be twisted? Aaaugh.
Much, much, much less nerve-wracking to recreate the whole section. In mulling over how to make this reasoning more explicit, I’ve come to a humbling realization. I admire Marianne Kinzel enormously, of course, but I’ve never been a big fan of her style of charting. I’ve always leaned more toward Barbara Walker’s… but today it hit me that - DUH! - one size doesn’t fit all in any aspect of knitting, and in many ways Kinzel’s approach works better for this pattern than Walker’s.
This is one of my early attempts at charting Peri’s Parasol, Walker-style, from Walker’s instructions:

Caveats: 1) This chart is Not Ready for Prime Time - it is semi-converted from flat to circular, and it doesn’t handle the difference between the framing stitches at the edges of a flat piece and the overlap stitches that occur between pattern repeats. 2) Neither this chart nor either of the subsequent ones corresponds precisely to the knitted lace in the photographs; the charts reflect the original Peri’s Parasol pattern, whereas the version I’m knitting includes several important modifications, not yet documented. Nevertheless, the structural principles are the same.
I’ve always liked this style of charting because it gives an approximate visual representation of the shape being knitted. Nevertheless, the fact that it doesn’t provide an efficient way to deal with the meeting of pattern repeats is a serious disadvantage. So this morning I sat down to experiment with the other approach, and here’s what I got:

It doesn’t look quite as much like the knitted fabric - bear in mind that the actual fan, or rather parasol, is represented here by the chunk on the right, the part that looks kind of like a city skyline - but I think it’s a more accurate reflection of what’s actually happening as you knit it. And the piece on the left has the great advantage of keeping the in-between section, the part I’ve been calling the negative fan, together, and showing it intact.
Here, take a closer look at the negative fan portion:

For purposes of demonstration and context I’ve reproduced both the trailing edge of one parasol figure and the leading edge of the next - that’s the two stacks of ‘B’ blocks, each one representing a single twisted stitch, worked through the back loop.
Now. Here are the two really important points about this whole tangled tale.
First - look at the center stitch in Row 1 of the chart. Now look at a detail from the last photograph. See the highlighted foundation stitch?

Same thing - right? But I think this style of chart layout makes it a lot easier to see how the whole section is built on that one stitch. The two twisted stitches in Row 3 correspond to the two YOs in Row 1, and in turn the YOs surrounding those become the base for the twisted stitches and decreases in Row 5, and so on. All 17 stitches of the negative fan, visibly traced back to that single stitch in Row 1.
That is why it was sane to rip and rebuild the section.
Next - look at the fan edges in the chart, the aforementioned vertical columns of twisted stitches. And now look at what they correspond to in the knitted lace:

(This is the potentially crazy-making thing about charting. Do you stack the stitches accurately in relation to each other, thus distorting the graphical representation of the pattern? or do you lay them out so they look more like the real result, at the risk of giving a less than accurate impression of their interactions? The answer to that, of course, is a compromise - some of each, in whatever combination will be most clearly understood and most easily followed. All these years of knitting, and I just figured that out today. Hmph.)
Those two diagonal lines of stitches only look like diagonals because they’ve been dragged and shoved and coaxed and finagled into that position by the forces of increasing and decreasing and clustering - but in their relationship to each other they are still vertical columns of stitches. Dropping the stitches that fall between them will not affect them in the slightest.
That is why it was safe to rip and rebuild the section.
Put those two facts together, and it becomes perfectly rational to ravel all 17 stitches back to the beginning of the repeat. (It is, however, awfully important to secure that one foundation stitch before doing so - otherwise you’re asking for trouble. Not insoluble trouble, but serious pain-in-the-neck trouble at best.)
Full disclosure on the lifeline front: I’m a pretty seat-of-the-pants knitter in a lot of ways, as a rule, and… um… I’ve never actually used a lifeline before (don’t think I’d ever even heard of them until maybe a year ago). I do think, though, that I picked a very good moment to start acting like a grown-up in this respect. Don’t you? Let us draw a distinction, however, between the knitter who doesn’t use lifelines and the knitter who expresses contempt for them. Even when I was flying without a net, I felt nothing but respect for knitters who were visibly more prudent and sensible than I. Conversely, you won’t ever find me casting the first stone at the knitter who gets into trouble for lack of a lifeline. There but for the grace….
Stealth Update
Still can’t show you the new-and-different Beige Blob or the sock-in-progress, but I think it’s safe to tell you that, thanks to an unexpected moment of Stash Archaeology, the projected Maroon Blob has decided to be a Green Blob instead.

Ahem… Excuse me. (Assistant included for, um, scale.)

Most fortuitously, it wasn’t until after I got this far that I suddenly remembered a little accident I’d had a week or so ago when I was wandering the remnant bins in search of lining fabric for the Beige Bag; wherein a couple of other and apparently unrelated remnants seem to have fallen into my basket when I wasn’t looking. It turns out that this happened for a reason - I just wasn’t aware of it at the time.

Greens are the bane of a photographer’s existence - and of mine as well -

- so you may just have to take my word for it that the color match here is simply uncanny. Normally I wouldn’t even want to try for such a thing. When I started knitting this Blob last night I assumed I would soon have to risk life and limb in the remnant bin again to find some cream-colored silk for a lining. But some things are just meant to be. This is a gift horse, and I don’t see me looking it in the mouth.