To recap if you haven't read my earlier posts...

A stray had been frequenting our house for over a month. He was
flea-bitten, mite-infested and hungry, but obviously socialized to
humans because he was so friendly.

We were at the time owned by two cats; Tiger, 10 yr old, farm cat
mutt/maine coon wannabe, and his newest best friend, Louis, a 2 yr old
Bengal. Tiger has lived with other cats before peacefully, and Louis
has never lived with any cat except his littermates and Tiger. We put
posters up, checked with the missing cats file at the humane society,
and determined that the stray was truly on his own. We got him fixed,
vaccinated, and began quaranteening him from the other cats in our
home.

Mid-summer, we began slowly introducing him to the residents. First
through a cracked door, then by close supervision in the same room.
Through this time, he'd attacked Louis and scarred his ear, and also
Tiger, leaving no marks. The two residents had nonetheless put up a
good fight, scarring him.

The stray, named Henry (because that's what he told me his name was)
is an overwhelmingly wonderful housecat - jumping onto our laps,
cuddling in bed, and playful and curious. He has become huge, so that
now we're dieting him, and he outweighs the other cats by several
pounds.

As Fall fell, we've taken to a routine of keeping him totally separate
from the other cats, since he's shown no interest in being friendly.

Tiger hides if he detects Henry is about, and Louis keeps a close eye.
Lately when transferring the cats, Louis has shown a great
determination to charge Henry, though I've always stopped him before
any more fur can fly. On the few occasions where they've moved too
fast for us to check them, Henry has been determined to kill Tiger,
and Louis will join in to defend his big brother.

The earlier responses I got here were none too encouraging.. some
folks saying it was months or years before their cats were integrated.
Now I'm looking for some new direction based on the long time we've
had them all in the same house but not mixing.

Would the "cut-a-hole-in-a-door" type suggestions still be fruitful at
this point? How about "let them fight it out to determine rank"?

We really can't go on like this much longer. There is no good place
for the second set of litterboxes, and I'm constantly stressed
wondering whether Louis has finally figured out how to open the door
behind which Henry lies in wait (Louis has proved ridiculously
inventive.. figuring out the ice machine, the front door, and the
cabinets. Like having a toddler that can jump six feet in the air.
Thank god he doesn't have opposable thumbs...)

Is it a hopeless case? Louis is smaller but ridiculously strong.. he
and Henry could do serious damage to each other, but they're both so
beautiful. Tiger is the world's sweetest cat, and I'd hate if anything
happened to him.

One idea I'd had was to put Henry in a kennel for a week or so, then
start over again. Other than that I fear my only other options are to
ship him out to a no-kill (still a horrible set of living conditions)
or try against odds to find someone to adopt him.

Grasping at straws. Sometimes it really sucks to love cats so much.

(Recent 10 year history since I'm feeling sorry for myself:

1991 Tom and Abbey were adopted from an uplanned litter
1992 Tom was killed by dogs when he snuck out of the house.. while I
uselessly clubbed and shouted at the dogs. I can't imagine any more
horrible experience. Still makes me cry..
2002 Abbey put to sleep with mammary cancer
1995-2001 Roy was discarded by a friend, and was put to sleep after a
gargantuan sarcoma developed on his back
1997-2000 Howard was almost dead at our doorstep.. he was
rehabilitated and three years later died from mysterious FIV-like
immune system disease.
1993-present - Tiger knew all of them except Tom, and treated them
like pals. Adopted from a farm, we took him to see Paul Bunyan. He'd
had a scrape with Howard when a stray wandered by our porch. Howard
had sliced his cornea, but he recovered and the two cats achieved a
grudging truce.)

Now Tiger's set to go into senior-citizenship, and I don't want to
ruin his retirement with an aggressive monster.

Sorry I'm so maudlin.. all the cat introductions we've had have gone
so smoothly. After 10 seconds of growls, Tiger began grooming the
kitten Louis, and they've been close ever since. We've never had to go
to these extremes before.

thanks for any ideas.

BLink