diff --git a/docs/ROADMAP.md b/docs/ROADMAP.md
index d5a3c8b..50efbc7 100644
--- a/docs/ROADMAP.md
+++ b/docs/ROADMAP.md
@@ -15,7 +15,7 @@ Design reference: [`specs/2026-06-04-human-experience-filter-design.md`](./super
 |---|---------------------------------|---------------|----------|
 | 1 | Catalog & Selection Core        | ✅ Done        | everything |
 | 2 | Ingest & Tagging / Review tools | ✅ Done        | a real library |
-| 3 | Player Runtime (Pi)             | ⏳ Next        | the room runs |
+| 3 | Player Runtime (Pi)             | ⏳ In progress | the room runs |
 | 4 | Arduino Firmware (control panel)| ◻ Not started | real knobs |
 | 5 | ~~Procedural Side Walls~~       | ❌ Dropped     | — (superseded) |
 
@@ -95,29 +95,60 @@ was `validate_catalog` + `index_by_id`.
 
 ---
 
-## 3. Player Runtime (Pi) ⏳ (next)
+## 3. Player Runtime (Pi) ⏳ (in progress)
 
-**Goal:** the thing that makes the room run — read the controls, pick media, play
-it across the single panoramic projector.
+**Goal:** the thing that makes the room run — read the controls, **alter** the
+neutral base footage toward the knob state, and play it across the single
+panoramic projector. Per the machine-altered-perception revision the knobs no
+longer *select* a pre-tagged clip; they drive an **alteration engine** (design
+§4/§5) over a small neutral base library.
 
-**Delivers (`player/`):**
+**Slice 1 — alteration engine + player core (pure logic) ✅ Done.** Merged to
+`main` (session 0006); 56 tests. The new `player/` package, with all I/O
+(video/audio/serial) behind injected interfaces:
 
-- Read the five control values from the Arduino over USB serial.
-- Call `hef.selection.select()` on each change; loop the chosen 5–15 min segment
-  until the knobs move; **crossfade** on change.
-- `None` mode → fade to black + silence.
-- Drive the **single panoramic projector** spanning the three walls with the real
-  selected video (no primary/side split; no side-wall feed — sub-project 5 dropped).
+- `player/controls.py` — `Controls`, the full panel state (7-way content dial +
+  4 experience knobs + volume + brightness); the serial-contract data shape
+  shared with sub-project 4.
+- `player/content.py` — `resolve_content`, the §6 7-way dial → (audio source,
+  video on/off) table.
+- `player/alteration.py` — `plan_alteration`, knob vector → `RenderPlan`
+  (mood `ColorGrade` with center=identity §5; Left `AnalyticalOverlay`; Right
+  `Restyle`), encoding the §4.2 layering rule (substrate vs overlay; Left & Right
+  stack).
+- `player/state.py` — `Player`, the state machine that diffs successive controls
+  into transitions (`FADE_TO_BLACK`/`FADE_FROM_BLACK` on video on/off,
+  `CROSSFADE` on clip/restyle-variant swap, `LIVE_UPDATE` for the continuous
+  grade/overlay/level ops per §4.3, `NONE` when unchanged).
 
-**Depends on:** sub-project 1 (`select`); a populated catalog from sub-project 2
-to be meaningful, but can be developed against a hand-authored catalog and a
-**keyboard/serial stand-in** before firmware exists.
-**Done when:** given a catalog and a stream of control values, it plays the
-correct segment, loops, crossfades, and goes dark on `None` — testable with the
-serial input mocked.
-**Hardware:** Raspberry Pi 5 (holds the drive + catalog).
+Plan: [`2026-06-05-player-alteration-core.md`](./superpowers/plans/2026-06-05-player-alteration-core.md).
+
+**Remaining slices (not started):**
+
+- **Runtime renderer** — drive the single panoramic projector via mpv/ffmpeg;
+  GPU shaders for the luma-keyed mood grade + analytical-overlay compositing;
+  realize crossfade/fade timing and the 5–15 min loop. (Open decision: player
+  stack — mpv via IPC vs. ffmpeg vs. custom.)
+- **Serial input** — real USB-serial reader on the Pi + the **3⇄4 framing
+  contract** with the firmware (the keyboard/serial stand-in already works via a
+  `Controls` stream).
+- **White-noise generation** — runtime white/pink noise for that content position.
+- **Offline v2v variant pipeline** — author the pre-baked Right restyle variants
+  (the only paid AI step, design §9) + the multilingual label/string tables + TTS.
+- **Catalog model changes** — audio *source* + "neutral base" vs "altered
+  variant" flag (sub-project 2 territory, design §13).
+
+**Depends on:** sub-project 1 (`Coordinate`); a neutral base library from
+sub-project 2 to be meaningful, but developable against a hand-authored library
+and a **keyboard/serial stand-in** before firmware exists.
+**Done when:** given a base library and a stream of control values, it plays the
+correct altered segment, loops, crossfades, and goes dark on `Off` — the
+decision logic is covered (slice 1, serial mocked); the renderer realizes it.
+**Hardware:** Raspberry Pi 5 (holds the drive + base library + variants).
 **Open decisions:** player stack (mpv via IPC vs. ffmpeg vs. custom); whether the
-player hard-restricts to `approved` records.
+player hard-restricts to `approved` records (the `approved_only` flag is plumbed
+but inert until backed by a real catalog); knob→strength calibration (the §3 vs
+§4.2/§5 reconciliation — see the slice-1 plan / session 0006 transcript).
 
 ---