Ben:

If Pud is unconscious from the attack, Ben will grab him and pull him ashore.  If Pud is more or less okay on his own, Ben will scramble up onto shore and draw his shield, moving towards the source of the arrows and calling down holy fire on the nearest foe he finds (move and cast Sacred Flame).

Sacred Flame : DC 14 Dexterity to negate, Radiant Damage: 8

Con Save: 20 (17 + 3 from Ben's aura)

Pud giggles "haha...that kinda stung. Was that a tooth pick? My turn!" Pud swims ashore towards the assailants. IF he see's any of the offending creatures, he will cast [spell]acid splash[/splash] on one of them. IF there are two within 5 ft of each other, he will target two of them.

Targets must make a DC 15 dex save or take 6 acid damage.

Matilda, Ben, Pud, and Elkhorn swim to shore, climb the muddy bank, and trudge across the muddy land through the thick fog toward the massive tree. They cannot see their assailants nor sort out exactly where the arrows came from. (It takes a Dash from the four of you to approach the tree close enough to see much, so no actions, not that you can see anyone to attack, anyhow. I can retcon that if you'd prefer to keep your distance.) Horatio may still move and/or act. Morgort groans and complains as she treads water near the horse, "I don't feel so good. We shouldn't be stopping to fight anything. Aren't we taking on the hag? Can we make this quick?"

Several holes dot the trunk of the gnarled old tree, which looks mostly dead. One end of a clothesline is tied to a high branch on the northwest side of the tree. Several old garments hang from the clothesline, the other end of which disappears into the fog hovering over the lake.

No more arrows are fired, but the shrill little insults keep coming. "What are you going to do, chop the tree down? Go back in the swamp, you cowards! You can't fight me!" 

Everyone may act.

" I mean....we could chop the tree down......or burn it....pour some oil in these holes and light it up...."

Intimidation- 22

"You wouldn't dare touch this tree!" calls out a shrill voice from above, their voice cracking a bit. "Go back to your swamp before we, I, get really mad. Cowards!" The voice sounds a little less confident.

Pud smirks. He snaps his fingers and conjures a mote of fire in his palm ( fire bolt ).

"Give me the word...and up in flames she goes."

"Fire? Fa!" scoffs a little voice from somewhere above. "What... too afraid to fight with steel?"

An arrow flies down from above. 

Tiny Arrow Attack vs. Pud: 25. Hit: 1 piercing damage, and Pud must succeed on a DC 10 CON save...

You got a glimpse of a small bow, together with a tiny arm and head, sticking out of one of the cavities in the barless trunk before it is quickly retracted.

Ben:

When he sees the arm and bow stick out and fire, Ben calls down holy flame on the offender (ignores cover).

Sacred Flame DC 14 Reflex to avoid:  9

”I can appreciate the irony of being called coward by one who hides in a hole in a tree, but I will NOT abide you shooting at my friends!” calls out Ben as he completes his spell.

Intimidation if warranted:  16

Con save: 12 (6 + 3 (from Ben) + 3 from 'Flash of Genius talent')

Pud spots the little arm and arrow flying towards him. He flinches and manages to avoid a direct hit, but the glancing strike leaves a slight burning and tingling sensation.

He returns fire at the assailant with fire bolt

Attack: 17 to hit for 8 fire damage.

Matilda is a little worried about what exactly she has started....she hopes the little thing surrenders....

Little archer: DC14 Dex Save vs. Sacred Flame: 14

Pud simultaneously hurls a mote of flame at the creature (which has three-quarters cover.) He misses, but the tree itself is seared.

There's a tiny muffled shriek as your attacker narrowly misses immolation from two sources.

But you suddenly feel the earth move, as the tree itself begins to writhe in painful reaction and tear its massive roots out of the ground. You hear whoops of victory somewhere inside the holes.

It's time to roll proper initiative!
   Annoying little archers: 11
   Giant animated looks-mostly-dead tree: 6
   Elkhorn: 21

Anyone who rolls higher than a 10 may act! There are no archers currently visible, but the tree itself is now actively hostile and ready to smash things.

Ben:

"You know, I don't really want to fight you, or this tree--I just want to pass by without getting filled full of arrows," says Ben in common, then repeats in Sylvan just in case the tree can understand.

Initiative:  10

Ben:

If there is no reaction from the tree or the cowardly archers, Ben says, "I suggest we just move on and ignore these annoying little pricks--from the arrows, of course.  I will cover us."  He moves up between the others and the danger, then settles into a defensive stance (Dodge).

Initiative: 19

"Yeah...tree...or whoever's shooting tiny arrows at us. Y'all attacked us first! We were just swimming!" 

Pud backs up to the edge of the embankment, couches down to make himself small, and prepares to dodge any attacks.

(( Initiative Check = 11, in DDB log ))
(( Persuasion Check = 19 (nat 20!) in DDB log ))

Horatio does his best to hold up his hands while moving through the water. "Ho there big fellow (in Common, to the tree but audible to everyone), we are not here for you lot! We came here to free this land from the tyranny of the Hags and return Prismeer to its rightful ruler. Would you not see that good be done? As you are clearly fearless warriors, why not join us in our quest? We are close to the final battle right now!" 

Elkhorn readies his blade, preparing to attack the tree if it strikes anyone in the party.

The tree has uprooted itself, revealing massive, grasping roots. It's difficult to judge its reaction to your entreaties. The little voices above remain quiet.

Matilda may still roll initiative and act if it's above 11.

Initiative- 18

Matilda stared at the giant tree and immediately regretted her life choices, " Run!"

Disengage. Dive in the water. Dash-Swim.