diff --git a/pom.xml b/pom.xml
index 58da79494..96e8782b4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -148,7 +148,7 @@
 			<dependency>
 				<groupId>org.projectlombok</groupId>
 				<artifactId>lombok</artifactId>
-				<version>1.12.6</version>
+				<version>1.16.4</version>
 				<scope>provided</scope>
 			</dependency>
 			<dependency>
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/MilliSpan.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/MilliSpan.java
new file mode 100644
index 000000000..da2a320a4
--- /dev/null
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/MilliSpan.java
@@ -0,0 +1,68 @@
+package org.springframework.cloud.sleuth.trace;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.Singular;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * @author Spencer Gibb
+ */
+@Data
+@Builder
+public class MilliSpan implements Span {
+	private final long begin;
+	private long end;
+	private final String description;
+	private final String traceId;
+	@Singular
+	private final List<String> parents;
+	private final String spanId;
+	private final Map<String, String> kVAnnotations;
+	private final String processId;
+	@Singular
+	private final List<TimelineAnnotation> timelineAnnotations;
+
+	@Override
+	public synchronized void stop() {
+		if (end == 0) {
+			if (begin == 0)
+				throw new IllegalStateException("Span for " + description
+						+ " has not been started");
+			end = System.currentTimeMillis();
+			//TODO figure out how to Trace.deliver(this)
+		}
+	}
+
+	@Override
+	public synchronized long getAccumulatedMillis() {
+		if (begin == 0)
+			return 0;
+		if (end > 0)
+			return end - begin;
+		return System.currentTimeMillis() - begin;
+	}
+
+	@Override
+	public synchronized boolean isRunning() {
+		return begin != 0 && end == 0;
+	}
+
+	@Override
+	public Span child(String description) {
+		return null;
+	}
+
+	@Override
+	public void addKVAnnotation(String key, String value) {
+		kVAnnotations.put(key, value);
+	}
+
+	@Override
+	public void addTimelineAnnotation(String msg) {
+		timelineAnnotations.add(new TimelineAnnotation(System.currentTimeMillis(), msg));
+	}
+
+}
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
index 48c8f656d..673b0d6be 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Span.java
@@ -1,5 +1,6 @@
 package org.springframework.cloud.sleuth.trace;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -20,12 +21,12 @@ public interface Span {
 	/**
 	 * Get the start time, in milliseconds
 	 */
-	long getStartTimeMillis();
+	long getBegin();
 
 	/**
 	 * Get the stop time, in milliseconds
 	 */
-	long getStopTimeMillis();
+	long getEnd();
 
 	/**
 	 * Return the total amount of time elapsed since start was called, if running,
@@ -51,13 +52,13 @@ public interface Span {
 	 * The spanId is immutable and cannot be changed.  It is safe to access this
 	 * from multiple threads.
 	 */
-	long getSpanId();
+	String getSpanId();
 
 	/**
 	 * A pseudo-unique (random) number assigned to the trace associated with this
 	 * span
 	 */
-	long getTraceId();
+	String getTraceId();
 
 	/**
 	 * Create a child span of this span with the given description
@@ -67,16 +68,9 @@ public interface Span {
 	/**
 	 * Returns the parent IDs of the span.<p/>
 	 * <p/>
-	 * The array will be empty if there are no parents.
+	 * The collection will be empty if there are no parents.
 	 */
-	long[] getParents();
-
-	/**
-	 * Set the parents of this span.<p/>
-	 * <p/>
-	 * Any existing parents will be cleared by this call.
-	 */
-	void setParents(long[] parents);
+	List<String> getParents();
 
 	/**
 	 * Add a data annotation associated with this span
@@ -108,9 +102,4 @@ public interface Span {
 	 * Will never be null.
 	 */
 	String getProcessId();
-
-	/**
-	 * Set the process id of a span.
-	 */
-	void setProcessId(String s);
 }
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/SpanHolder.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/SpanHolder.java
new file mode 100644
index 000000000..38a054b16
--- /dev/null
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/SpanHolder.java
@@ -0,0 +1,16 @@
+package org.springframework.cloud.sleuth.trace;
+
+/**
+ * @author Spencer Gibb
+ */
+public class SpanHolder {
+	private static final ThreadLocal<Span> currentSpan = new ThreadLocal<>();
+
+	public Span getCurrentSpan() {
+		return currentSpan.get();
+	}
+
+	public void setCurrentSpan(Span span) {
+		currentSpan.set(span);
+	}
+}
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
index 0728c44ab..6c1f57ea4 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/Trace.java
@@ -1,5 +1,7 @@
 package org.springframework.cloud.sleuth.trace;
 
+import java.util.Collection;
+
 /**
  * The Trace class is the primary way to interact with the library.  It provides
  * methods to create and manipulate spans.
@@ -85,4 +87,6 @@ public interface Trace {
 	 * @return Span representing the current trace, or null if not tracing.
 	 */
 	public Span currentSpan();
+
+	public void setSpanReceivers(Collection<SpanReceiver> spanReceivers);
 }
diff --git a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceScope.java b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceScope.java
index f138a5afa..803f84f4f 100644
--- a/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceScope.java
+++ b/spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/trace/TraceScope.java
@@ -1,7 +1,42 @@
 package org.springframework.cloud.sleuth.trace;
 
+import lombok.Data;
+
+import java.io.Closeable;
+import java.io.IOException;
+
 /**
  * @author Spencer Gibb
  */
-public class TraceScope {
+@Data
+public class TraceScope implements Closeable {
+	/**
+	 * the span for this scope
+	 */
+	private final Span span;
+
+	/**
+	 * the span that was "current" before this scope was entered
+	 */
+	private final Span savedSpan;
+
+	private boolean detached = false;
+
+	/**
+	 * Remove this span as the current thread, but don't stop it yet or
+	 * send it for collection. This is useful if the span object is then
+	 * passed to another thread for use with Trace.continueTrace().
+	 *
+	 * @return the same Span object
+	 */
+	public Span detach() {
+		//TODO: implement detach
+		return span;
+	}
+
+	@Override
+	public void close() throws IOException {
+		span.stop();
+		//TODO: set savedSpan to currentSpan in SpanHolder
+	}
 }